Contents
 

Bacterial, mycotic and parazitic diseases; viruses



5  Non-tumorous skin diseases

5.14  Bacterial, mycotic and parazitic diseases; viruses

5.14.1  Bacterial inflammations with suppuration, pyodermia

Introduction:

Pyodermia affects the epidermis (impetigo), adnexa (folliculitis), dermis and subcutis (phlegmone).

Histology:

Phlegmone: dense dermal infiltrate with many neutrophils, abscesses, necroses.

Pictures

Phlegmone of the scrotum:
Phlegmone of the scrotum, HE 40x (13004)

5.14.1.1  Erosive pustulosis of the head

Clinical signs:

  • rare disease of unknown ethiology
  • location: scalp
  • chronic active inflammation, shallow ulcers
  • scarring alopecia

Histology:

Infiltrate of variable intensity with neutrophils, reactive changes of surrounding epidermis, scarring alopecia.

5.14.1.2  Erysipelas

Etiology:

Infection by group A Streptococci.

Clinical signs:

  • localization: lower extremities, face, upper extremities with lymphedema
  • at first nausea, then fever
  • reddish skin plaques
  • irregular lateral spread
  • painful regional lymphnode, lymphanigitis
  • recurrencies often
  • lymphedema after damage of the lymphatic vessels

Pictures

Erysipelas, irregular spread:
Erysipelas, CLINIC (726)

Erysipelas, bullous:
Erysipelas, CLINIC (727)

Erysipelas, foot:
Erysipelas, CLINIC (728)

Erysipelas, upper extremities (following lymphadenectomy):
Erysipelas, CLINIC (729)

Erysipelas:
Erysipelas, CLINIC (2895)

Erysipelas, CLINIC (2896)

Cellulitis cruris:
Erysipelas, cellulitis cruris, Macro (3729)

Erysipelas, cellulitis cruris, Macro (3730)

Erysipelas, cellulitis cruris, Macro (3731)

Further examples of erysipelas:

Histology:

Edema of superficial dermis, bacteria, mixed interstitial infiltrate with neutrophils, dilated capillaries and lymphatics.

Pictures

Erysipelas:
Erysipelas, HE 40x (4766)
  [zoomify]

Erysipelas:
Erysipelas, HE 20x (4246)

Erysipelas:
Erysipelas, HE 10x (530)

Erysipelas, HE 40x (531)

Another case:
Erysipelas, HE 40x (2276)

Another case, with baloon degeneration of the epidermis:
Erysipelas, HE 20x (4241)

Another case:
Erysipelas, HE 20x (4242)
  [zoomify]

Another case, chronic erysipel:
Erysipelas, chronic, HE 20x (4243)
  [zoomify]

5.14.1.3  Sepsis (bacterial)

Clinical signs:

  • multiple lesions, general condition alterated
  • low reactivity in immunodefficient pacients
  • usually accomanied by bleeding to the skin

Histology:

Leukocytoclastic vasculits, fibrin thrombi, perivascular and interstitial infiltrates with neutrophils, bleeding. Special staining may show the bacteria.

Epidermis is often necrotic, spongiotic or with pustules.

5.14.1.4  Erysipeloid

Etiology:

  • acute bacterial infection of traumatized skin
  • caused by bacteria Erysipelothrix rhusiopathiae

Clinical signs:

  • occupational disease, common among farmers, butchers, cooks
  • acute, self-limited infection of the skin
  • rarely other organs may be affected (endocarditis)
  • resolves usually without consequences
  • lesions are well-demarcated, violaceous plaques with an advancing border and central clearing

Histology:

The epidermis shows spongiosis and sometimes vesiculation. Marked edema of the papillary dermis, dilatation of lymphatic vessels. In the reticular dermis, a perivascular inflammatory infiltrate with lymphocytes, neutrophils and eosinophils.

Pictures

Erysipeloid:
Erysipeloid, HE 20x (4245)
  [zoomify]

5.14.1.5  Ecthyma

Etiology:

Minor trauma infected by group A Streptococci.

Clinical signs:

  • small inflammed bulla gets necrotic, escharotic inflammation develops into shallow ulcer or ulcers covered by crust
  • healing is slow; leads to scars
  • age: children
  • location: usually extremities

Histology:

Edema, neutrophilic infiltrate, necrosis, necrotizing ulcer; Streptococci are often present within the necrotic tissue.

Pictures

Ecthyma:
Ecthyma, HE 40x (5481)

5.14.1.6  Orf

Etiology:

  • Orf virus (poxvirus)
  • transmission from animals (goats, sheep)
  • transmission by direct contact
  • butchers and other professionals

Clinical signs:

  • localization: most often fingers (dorsal aspects), one or several lesions
  • papule changing into vesicle or pustule, covered by crust
  • size of the lesion is 1 – 3 cm
  • lesions spontaneously dissapear after 3 – 6 weeks
  • sometimes accompanied by increased temperature and/or lymphadenopathy

Histology:

Intraepidermal vesicle (baloon degeneration), intracytoplasmatic inclusions. Lymphocytic infiltrate with some eosinophils or neutrophils. Later necrosis covered by crust.

Pictures

Orf:
Orf, HE 20x (4901)
  [zoomify]

5.14.1.7  Angulus infectiosus
5.14.1.8  Aphta

Clinical signs:

  • painful single or multiple, whitish lesions of oral mucosa
  • heal spontaneously, without scaring
  • etiology is unknown

Histology:

Shallow ulcer, covered by fibrin and neutrophils.

5.14.1.9  Phlegmone, gangrene

Clinical signs:

  • spreads from the focus of primary infection
  • reddish, firms plaque
  • unsharp borders, can affect the fascia or muscle
  • tendency towards necrosis

Pictures

Phlegmone:
Phlegmone, CLINIC (739)

Diabetic gangrene:
Phlegmone, CLINIC (740)

Histology:

Dense dermal infiltrate with many neutrophils, dermal edema and often bacteria. Blood vessels may be thrombosed. Epidermis is often partially or completely necrotic with subepidermal separation and often large bullae.

Pictures

Phlegmone of the scrotum:
Phlegmone, HE 40x (2671)

Phlegmone (35 years old woman, multiple sclerosis, paresis, phlegmone; autopsy case):
Phlegmone, HE 40x (2670)

Dry gangrene, diabetic:
Dry gangrene, vascular necrosis of the skin, HE 40x (2672)

5.14.1.10  Erythrasma

Etiology:

Clinical signs:

  • inguinae, axillae
  • patches with sharp borders, slight squames
  • color: light brown to red-brown
  • no inflammatory borders

Pictures

Erythrasma:
Erythrasma, CLINIC (1051)

Erythrasma:
Erythrasma, CLINIC (2925)

Further examples of erythrasma:

Histology:

Gram positive, PAS slightly positive rods and filaments within the horny layer.

Pictures

Erythrasma, possible association with lichen sclerosus et atrophicus:
Erythrasma, HE 40x (2554)

Erythrasma, PAS 40x (2555)

Erythrasma, Gram 40x (2553)

Lichen sclerosus et atrophicus and erythrasma:
Erythrasma, lichen sclerosus, pruritus vulvae, HE 100x (4896)
  [zoomify]

5.14.1.12  Borreliosis

Introduction:

Diseases caused by the spirochete Borrelia burgdorferi, transmited by the tick Ixodes.

5.14.1.12.1  Erythema chronicum migrans

Clinical signs:

  • 1st stage of borreliosis
  • usually in the site of the bite, lesions can be multiple
  • erythema spreads slowly, gets pale in the center
  • no pain, no scaling

Pictures

Erythema chronicum migrans, chest:
Erythema chronicum migrans, CLINIC (1040)

Erythema chronicum migrans, detail:
Erythema chronicum migrans, CLINIC (1041)

Erythema chronicum migrans, arm:
Erythema chronicum migrans, CLINIC (1042)

Erythema chronicum migrans, trunk:
Erythema chronicum migrans, CLINIC (2909)

Erythema chronicum migrans, CLINIC (2910)

Erythema chronicum migrans, trunk:
Erythema chronicum migrans, CLINIC (2913)

Erythema chronicum migrans, arm:
Erythema chronicum migrans, CLINIC (2911)

Erythema chronicum migrans, CLINIC (2912)

Erythema chronicum migrans, knee:
Erythema chronicum migrans, CLINIC (2914)

Erythema chronicum migrans:
Erythema chronicum migrans, CLINIC (6098)

Erythema chronicum migrans, CLINIC (6099)

Further examples of erythema chronicum migrans:

Histology:

Perivascular lymphocytic infiltrate with admixture of plasmocytes. Silver impregnation sometimes reveals the spirochetes.

5.14.1.12.2  Borreliosis (acrodermatitis chronica atrophicans)

Clinical signs:

  • skin lesions of the 3rd stage of borreliosis
  • location: extremities, often unilateral involvement
  • atrophic skin with visible blood vessels
  • color: red or purple
  • involvement is widespread (often affects the whole extremity)

Pictures

Acrodermatitis chronica atrophicans, dorsa or the hands
Acrodermatitis chronica atrophicans, CLINIC (961)

Further examples of acrodermatitis chronica atrophicans:

Histology:

Perivascular infiltrate, superficial and deep, of variable density; usually with variable admixture of plasma cells. Epidermis is atrophic, thinned, without rete ridges. Loss of hair adnexa in long standing lesions. Slight dermal edema may be present in active lesions.

5.14.1.13  Adnate listeriosis

Etiology, pathogenesis:

  • caused by bacteria Listeria monocytogenes, which is especially dangerous for immunosupressed individuals and pregnant women
  • contaminated foodstuffs (non-pasteurised milk and other) are the source of infection
  • placenta and later the fetus are infected by hematogenic and ascendent mode of infection (the fetus swallows infected amniotic fluid)
  • the fetus develops disseminated infection affecting many organs

Clinical signs:

  • slight elevation of body temperature, increased inflammatory markers
  • spontaneous healing after abortion or delivery
  • spontaneous abortion, premature delivery of dead or heavily infected newborn

Histology:

Multiple small necroses, infiltrated by neutrophils.

Pictures

Listeriosis, aborted fetus (fetal skin, necrosis, autolysis; the same case as above):
Listeriosis (aborted fetus), HE 40x (5508)

5.14.1.14  Nail infection caused by Pseudomonas

Clinical signs:

Chronic infection of the nails, often with greenish discoloration.

5.14.2  Mycobacteria, actinomycetes

5.14.2.1  Tuberculosis cutis

Introduction:

  • TBC cutis with immune response: tbc cutis verrucosa, lupus vulgaris, scrophuloderma, tuberculids
  • Lupus vulgaris
  • TBC verrucosa: verrucous, later atrophic lesions of the hands; infection is exogenic: through small skin trauma
  • Scrophuloderma: subcutaneous, spread of infection from the lymphnodes, bones etc.; inflammatory nodules, fistulae, scarring, most often on the neck
  • Tuberculids: rare symmetric lichenoid and papulonecrotic eruptions (papulonecrotic tuberculid, lichen scrofulosum)
  • Erythema induratum Bazin: vasculitis considered to be the deep tuberculid; inflammatory necrotizing nodules of the calves

Etiology:

Tuberculosis is caused by Mycobacterium tuberculosis

5.14.2.1.1  Scrophuloderma

Clinical signs:

  • draining tuberculosis of internal organs (lymphatic nodes, eg. cervical), bone etc.
  • painless swelling
  • ulceration

Pictures

TBC, scrophuloderma:
Tuberculosis, CLINIC (1094)

Histology:

Granulomas with giant cells of Langhans, lymphocytes, plasmocytes and neutrophils, tuberculous pus, draining fistula; unspecific epidermal proliferation.

Pictures

Scrophuloderma:
Scrofuloderma, HE 2x (612)

Scrofuloderma, HE 40x (613)

Scrofuloderma, HE 40x (614)

Scrophuloderma, histology corresponds to purulent inflammation; acid fast staining for mycobacteria is positive:
Scrofuloderma, HE 40x (4033)

Scrofuloderma, Ziehl Neelsen 40x (4032)

5.14.2.1.2  Lupus vulgaris

Clinical signs:

  • face, acral areas
  • more frequent in women
  • nodules, infiltrated plaques, verrucosities
  • lesions covered with atrophic skin
  • slow spread
  • red-brown color
  • lupomas can be demonstrated by diascopy
  • healing with atrophic and mutilating scarrs, recurrecnes common

Pictures

Lupus vulgaris, knee
Tuberculosis, CLINIC (1090)

Lupus vulgaris
Tuberculosis, CLINIC (1091)

Lupus vulgaris, mutilation of the nose
Tuberculosis, CLINIC (1092)

Lupus vulgaris, cheek
Tuberculosis, CLINIC (1093)

Papulonecrotic tuberculid
Tuberculosis, CLINIC (1096)

Tbc verrucosa
Tuberculosis, CLINIC (1097)

Histology:

Epitheloid granulomas (epitheloid cells, lymphocytes, multinuclear giant cells of Langhans), plasmatic cells, sometimen neutrophils; granulation tissue and fibrosis, verrucous and pseudoepitheliomatous hyperplasia of the epidermis or atrophy. Caseous necrosis is present only sometimes, and usually not pronounced. Special stainings for mycobacteria are usually negative.

5.14.2.1.3  Reaction to BCG vaccination or sensitivity tests

Clinical signs:

Chronic granulomatous inflammation with epitheloid granulomas in the site of vaccination.

Pictures

Vaccination reaction:
Tuberculosis, CLINIC (1088)

Bullous MTX II test, positive for TBC:
Tuberculosis, CLINIC (1095)

Histology:

Chronic granulomatous inflammation with epitheloid granulomas in the site of vaccination. Inflammation, variable necrosis, epitheloid granulomas with Langhans cells.

Pictures

Reaction to BCG vaccination:
BCG vaccination,atypical reaction, HE 40x (6042)

5.14.2.1.4  Papulonecrotic tuberculid

Clinical signs:

  • symmetric erythematous papular reaction
  • ulcerations, scarring

Histology:

Deep infiltrate, wedge shaped, granuloma with caseous necrosis, giant multinuclear cells. Sometimes thrombosed blood vessels are present. Special stainings for mycobacteria are negative.

5.14.2.2  Diseases caused by atypical mycobacteria

Clinical signs:

  • nodules, ulcerations and verrucosities at the site of trauma; slow spread
  • lymphatic and hematogenic spreading
  • swimming pool granuloma: infections from swimming pools or fish tanks
  • generalisation in immunodeficiencies (AIDS)

Pictures

Mycobacteriosis:
Tuberculosis, CLINIC (1087)

Histology:

Granulomatous inflammation, necroses; staining for mycobacteria similar to tuberculosis

Case study:

Atypical mycobacteriosis
MUDr. Hana Jedličková, PhD.

Introduction:

The incidence of skin infections caused by atypical mycobacteria is rising. They occur either in predisposed, i.e. immunocompromised individuals, or in case of long lasting contact of infectious agent with the skin.

Cutaneous manifestations are solitary or multiple nodules, pustules, ulcers or plaques. In immunocompetent individuals the disease is localized and sometimes self healing, though in immunocompromised patients the infection can be generalized and life threatening.

Classification:

Mycobacteria are acid-fast bacilli. Atypical mycobacteria are facultative human pathogens; they are divided into slow-growing and rapid growing mycobacteria, further into subgroups according to their pigment-forming properties.

Among the most frequent causes of skin diseases are M. marinum (fish tank granuloma), M. chelonae (e.g. catheter infections, surgery complications), M. kansasii, M. ulcerans (Buruli ulcer).

The pathogen can be identified by histopathology (Ziehl Neelsen stain), cultivation under special conditions and PCR (reference laboratories).

History:

51-year-old man had a 6-month history of dermatitis on his hands, treated by topical corticosteroids and 3-week history of erythematous nodules on the 3rd and 4th fingers of his right hand. He used medication for hypertension and hyperlipidemia. He was a professional aquarist for many years.

Clinical signs:

Two red nodules on the 3rd and 4th finger of the right hand.

Histology:

Epidermis showed hyperkeratosis and acanthosis. In the dermis there was a dense lymphocytic infiltrate and epitheloid granulomas with scattered multinuclear giant cells. In the centre of some granulomas were abscesses with numerous neutrophils. Ziehl Neelsen stain was positive with several rod-like microorganisms.

Special studies were performed by prof. Pavlík of the Reference Laboratories of Paratuberculosis and Avian Tuberculosis Mycobacteriology Unit, Veterinary research Institute, Brno. PCR studies were negative. In culture mycobacteria were detected after 9 weeks, which were further identified as Mycobacterium marinum.

5.14.2.3  Leprosy

Introduction:

Caused by Mycobacterium leprae; affects the skin and peripheral nerves. According to the immunity of the patient, the leprosy can be divided into six forms.

Tuberculoid leprosy, TT in patients with a high degree of immunity, borderline tuberculoid form, BT, true borderline form BL, borderline lepromatous form BL and lepromatous form LL in patients with the least degree of resistence (and this form is further divided into subpolar, LLs and polar, LLp forms.

Pictures

Lepra, hands:
Lepra, hands, CLINIC (4179)

Further examples of leprosy:

Histology:

Epitheloid granulomas with multinuclear Langhans giant cells, usually without necrosis in tuberculoid form. Infiltration and destruction of peripheral nerves is typical.

In lepromatous form there are nodular or diffuse infiltrates consisting of many lymphocytes and macrophages. Nerves are infiltrated as well. No giant cells are present. Later foamy cells appear. Staining for mycobacteria is positive.

For detailed histologic descriptions of various forms of leprosy see specialized literature.

Pictures

Specimens of two patients, suffering from lepromatous leprosy; specimens were taken from the thigh; multiple nodules over the whole body lasting 5 – 6 years; loss of sensation over palms and feet (Anandaban Hospital, Leprosy Mission Nepal, Kathmandu); HE, Fite for mycobacteria:
Leprosy lepromatous, HE 60x (10217)

Leprosy lepromatous, HE 60x (10218)

Leprosy lepromatous, HE 60x (10219)

Leprosy lepromatous, HE 60x (10220)

Leprosy lepromatous, Fite 60x (13299)

Leprosy lepromatous, Fite 60x (13300)

Leprosy (borderline tuberculoid):
Leprosy, borderline tuberculoid, HE 20x (4331)

Lepra, tuberculoid:
Leprosy tuberculoid, HE 40x (13175)

Leprosy, HE 60x (13071)

Special staining for acidoresistent mycobacteria Mycobacterium leprae is positive in low resistant patients (Lepromatous leprosy)
Mycobacterium leprae, HE (324)

Mycobacterium leprae, Fite (317)

Lepromatous leprosy:
Lepromatous leprosy, HE (315)

Lepromatous leprosy, detail:
Lepromatous leprosy, HE (316)

Tuberculoid leprosy, TT:
Tuberculoid leprosy, HE (418)

Tuberculoid leprosy, TT, detail:
Tuberculoid leprosy, HE (419)

Another case:
Leprosy, HE 2.5x (1393)

Leprosy, HE 20x (1392)

5.14.2.4  Actinomycosis

Introduction:

Actinomycosis (caused by Actinomyces israelii)

Clinical signs:

  • deep, draining abscesses
  • purulent chronic inflammation
  • purulent discharge with tiny granules

Pictures

Dental sinus is often caused by actinomycetic infection:
Dental sinus, Macro (3743)

Dental sinus, Macro (3744)

Dental sinus, Macro (3745)

Histology:

Purulent, mixed infiltrate (neutrophils, eosinophils, plasma cells, histiocytes), granulation tissue, pseudoepitheliomatous hyperplasia of the surrounding epidermis. Lobulated colonies of these bacteria (30 – 3000 µm) are typical, but not always present.

Case study:

Actinomycosis
MUDr. Hana Jedličková, PhD.

Etiology:

Actinomycosis is a chronic, suppurative infection caused by saprophytic gram-positive bacteria actinomycetes (Actinomyces israelii), which can be present in the mouth and gastrointestinal tract in healthy individuals.

Actinomycetes can be detected in smears, histology (Giemsa, Gomori stains) and by cultivation.

Clinical signs:

Most common is the cervicofacial involvement. Infection occurs in the sites of trauma (i.e. dental procedures) resulting in abscesses with sinus tracts draining pus. The surrounding skin is inflamed and indurated. Thoracic and abdominal involvement is also possible. In immunocompromised individuals the clinical presentation may vary (disseminated lesions, chronic skin infiltrates, etc.).

History:

51-year-old man had a 6-month history of an indurated red plaque with pustules on the dorsal aspect of his right hand. The lesion appeared two weeks after a minor skin injury by a saw in the garden. He was treated with amoxicilin and itraconazole (positive cultivation of trichophyton mentagrophytes) without clinical effect.

The patient had type 2 diabetes mellitus and hypertension; he was working as a plumber.

Clinical signs:

An indurated red plaque 7×5 cm with many small pustules and crusts on the dorsal aspect of the hand, on the third finger a healed scar after the trauma.

Pictures

Actinomycosis, hand:
Actinomycosis, CLINIC (6150)

Histology:

Pseudoepitheliomatous hyperplasia and suppurative granulomas with positive granules in the Giemsa stain. The granules are basophilic with eosinophilic halo (Splendore-Hoeppli phenomenon).

Pictures

Actinomycosis:
Actinomycosis, Giemsa 40x (6102)

5.14.3  Rhinoscleroma

Introduction:

Chronic inflammation of the upper respiratory tract

Etiology, pathogenesis:

Clinical signs:

  • affects nose, pharynx, larynx and trachea
  • firm infiltrates
  • chronic course

Histology:

Mixed diffuse infiltrate of the upper and lower dermis (lymphocytes, plasmocytes, neutrophils); Mikulicz cells (large macrophages with foamy cytoplasm), Russel bodies. Special stainings: Giemsa, silver impregnation, PAS.

5.14.4  Mycotic diseases

5.14.4.1  Superficial tinea

Clinical signs:

  • affects the skin, scalp, hairy areas, nails
  • pink, spreading plaques with scaling in the border and healing in the center; fragile hairs
  • often in intertriginous areas
  • nails: most commonly spreas from the free margin of the nail; white streaks, thickenning of the nail plate; fragmentation of the nail
  • excoriations sometimes
  • cultivation, Potassium Hydroxide test
  • Pityriasis versicolor forms brown or pale patches

Pictures

Tinea cruris:
Tinea, CLINIC (850)

Tinea interdigitalis pedis with secondary infection:
Tinea, CLINIC (851)

Superficial tinea, healing in the center:
Tinea, CLINIC (854)

Superficial tinea, arm:
Tinea, CLINIC (855)

Hyperkeratotic tinea, soles:
Tinea, CLINIC (1027)

Id dyshidrotic eruption, hand:
Tinea, CLINIC (1028)

Generalized superficial tinea:
Tinea, CLINIC (1029)

Onychomycosis affects especially lower extremities:
Tinea, CLINIC (1030)

Tinea, CLINIC (849)

Pityriasis versicolor:
Tinea, CLINIC (1031)

Pityriasis versicolor alba:
Tinea, CLINIC (1032)

Rubrophyton, buttocks:
Tinea, CLINIC (1033)

Rubrophyton, inguinal areas:
Tinea, CLINIC (1034)

Trichophyton, soles:
Tinea, CLINIC (1035)

Trichophyton, forearm:
Tinea, CLINIC (1036)

Trichophyton, lower extremity:
Tinea, CLINIC (1037)

Trichophyton, trunk:
Tinea, CLINIC (1038)

Pityriasis versicolor:
Tinea versicolor brown, CLINIC (3257)

Tinea versicolor brown, CLINIC (3259)

Tinea versicolor brown, CLINIC (3260)

Tinea versicolor brown, CLINIC (3261)

Pityriasis versicolor:
Tinea versicolor brown, CLINIC (3262)

Tinea versicolor brown, CLINIC (3258)

Pityriasis versicolor, var. rubra:
Tinea versicolor brown, Macro (3926)

Tinea versicolor brown, Macro (3925)

Tinea corporis:
Superficial mycosis, trunk, CLINIC (3356)

Superficial mycosis, trunk, CLINIC (3359)

Superficial mycosis, trunk, CLINIC (3360)

Superficial mycosis, trunk, CLINIC (3361)

Superficial mycosis, trunk, CLINIC (3362)

Superficial mycosis, trunk, CLINIC (3363)

Superficial mycosis, trunk, CLINIC (3357)

Superficial mycosis, trunk, CLINIC (3358)

Pityriasis versicolor:
Tinea versicolor brown, CLINIC (5832)

Tinea versicolor brown, CLINIC (5833)

Tinea versicolor brown, CLINIC (5834)

Tinea versicolor brown, CLINIC (5835)

Tinea versicolor brown, CLINIC (5836)

Tinea versicolor brown, CLINIC (5837)

Trichomycosis axillaris:
Trichomycosis axillaris, CLINIC (3396)

Trichomycosis axillaris, CLINIC (3397)

Trichomycosis axillaris, CLINIC (3398)

Tinea cruris, caused by Trichophyton mentagrophytes:.
Superficial mycosis, trichophyton mentagrophytes, CLINIC (3364)

Tinea faciei:
Superficial mycosis, CLINIC (3365)

Superficial mycosis, CLINIC (3366)

Tinea inguinalis:
Superficial mycosis, inguinalis, CLINIC (3367)

Superficial mycosis, CLINIC (3368)

Superficial inguinal mycosis, CLINIC (3369)

Superficial inguinal mycosis, CLINIC (3370)

Superficial inguinal mycosis, CLINIC (3371)

Tinea interdigitalis, leg:
Superficial interdigital mycosis, CLINIC (3372)

Superficial interdigital mycosis, CLINIC (3373)

Superficial interdigital mycosis, CLINIC (3374)

Tinea, hands:
Superficial mycosis, CLINIC (3375)

Superficial mycosis, CLINIC (3376)

Superficial mycosis, CLINIC (3377)

Tinea, hands:
Superficial mycosis, CLINIC (3378)

Superficial mycosis, CLINIC (3379)

Superficial mycosis, CLINIC (3380)

Tinea, hands:
Superficial mycosis, CLINIC (3381)

Superficial mycosis, CLINIC (3382)

Superficial mycosis, CLINIC (3383)

Superficial mycosis, CLINIC (3384)

Superficial mycosis, CLINIC (3385)

Tinea, leg:
Superficial mycosis, CLINIC (3386)

Tinea, leg:
Superficial mycosis, CLINIC (3387)

Superficial mycosis, CLINIC (3388)

Superficial mycosis, CLINIC (3389)

Superficial mycosis, CLINIC (3390)

Pityriasis versicolor, alba:
Tinea versicolor alba, CLINIC (5827)

Tinea versicolor alba, CLINIC (5828)

Tinea versicolor alba, CLINIC (5829)

Tinea of gluteal region:
Mycosis superficial eczematoid, CLINIC (5903)

Mycosis superficial eczematoid, CLINIC (5904)

Tinea during steroid therapy, the last image shows improvement after antimycotic therapy:
Mycosis superficial eczematoid, CLINIC (5906)

Mycosis superficial eczematoid, CLINIC (5907)

Mycosis superficial eczematoid, CLINIC (5908)

Mycosis superficial eczematoid, CLINIC (5909)

Mycosis superficial eczematoid, CLINIC (5905)

Interdigital tinea, legs:
Mycosis interdigitalis pedum, onychomycosis, CLINIC (5910)

Mycosis interdigitalis pedum, onychomycosis, CLINIC (5911)

Tinea, hands:
Superficial mycosis of the hands, CLINIC (5912)

Superficial mycosis of the hands, CLINIC (5913)

Tinea, hands:
Superficial mycosis capillitii, CLINIC (5914)

Superficial mycosis capillitii, CLINIC (5915)

Tinea, hair:
Superficial mycosis capillitii, CLINIC (5916)

Superficial mycosis capillitii, CLINIC (5917)

Microsporon tinea:
Microsporon mycosis, Grocott 40x (3576)

Further examples of dermatophyte infections:

Further examples of pityriasis versicolor:

Histology:

Inflammatory reaction is variable, fungi can be demonstrated using PAS or Grocott staining.

5.14.4.1.1  Candidosis

Clinical signs:

  • location: intertriginous, (inguinal regions, genital, under the breasts, skin fold in obese persons), oral cavity, nail folds
  • color: red
  • rhagades, maceration, pustules on the borders
  • pruritus, burning

Histology:

Hyphae of the upper partis of the corneal layer, PAS positive. Changes in HE stained slides are often inconspicuous (focal parakeratosis, neutrophils within the corneal layer).

5.14.4.1.2  Tinea nigra

Clinical signs:

  • superficial mycotic infection
  • location: usually soles

Histology:

Spaces within thick cornified layer, colonized by mycotic hyphae.

5.14.4.1.3  Dermatophyton

Introduction:

MUDr. Zdenka Rozkosna

Hyphae of Dermatophyta, native, KOH and ink staining (Parker).

5.14.4.3  Deep mycotic processes

Introduction:

Frequent in immunosuppressed patients; sometimes with dissemination.

Clinical signs:

  • lesion with inflammatory induration, pustules, loss of hairs from suppurating follicles,
  • multifocal discharge of pus after compression (kerion Celsi)
  • nails: most commonly spreas from the free margin of the nail; white streaks, thickenning of the nail plate; fragmentation of the nail

Pictures

Deep mycosis (Trichophyton), neck:
Tinea, CLINIC (852)

Deep mycosis (Trichophyton), hand:
Tinea, CLINIC (853)

Trichophytia profunda, chin:
Tinea, CLINIC (856)

Histology:

Mycotic microogranisms are present deep within the dermis (and often deeper). Special staining: silver impregnation (Grocott) or PAS, cryptococcosis: alcian blue and mucicarmine stains mucinous capsule.

5.14.4.3.1  Cryptococcosis

Etiology:

Caused by the fungus Cryptococcus neoformans.

Clinical signs:

  • variable papules, pustules, nodules, abscesses, ulcers
  • + systemic manifestations (respiratory tract, CNS, bones, prostate, kidneys, lymphnodes)
  • may be widespread

Histology:

Roundish spore, 4 – 12 µm with (but only 2 – 4 µm without) capsule. The gelatinous capsule stains with alcian blue, PAS and mucicarmine. Granulomatous inflammation (histiocytes, lymphocytes, giant cells, necrosis) is usually present (less inflammation when forms with gelatious capsules dominate).

5.14.4.3.2  Sporotrichosis

Histology:

Sporotrichosis: inflammatory dermal granulomatous infiltrate, sporotrichon is present within the cytoplasm of large, multinuclear histiocytes; dense infiltrate with plasma cells and neutrophils.

5.14.4.4  Onychomycosis

Clinical signs:

  • the disease spreads most commonly from the free margin of the nail (distal, Trichophyton rubrum); sometimes the involvement is proximal. Superficial involvement is usually caused by Trichophyton mentagrophytes. The fourth type of onychomycosis is caused by Candida.
  • white streaks, thickenning of the nail plate; fragmentation of the nail

Histology:

Nail plate and nail bed with mycotic hyphae; sometimes onycholysis; parakeratosis, hyperkeratosis of the nail bed

5.14.5  Diseases caused by parasites

5.14.5.1  Leishmaniasis

Introduction:

Nodular leishmaniasis contain many macrophages, epitheloid cells and plasmocytes. Leishmania donovani can be found in the cytoplasm of histiocytes.

Etiology:

Pictures

Leishmania under electron microscope:
Leishmania, electron microscope (6055)

Clinical signs:

  • 3 forms: localized cutaneous, mucocutaneous and visceral
  • location: usually face or extremities
  • ulcerating nodules, may be several cm in size
  • crusts sometimes
  • heals after several months with scar

Pictures

Leishmaniasis, hand:
Leishmaniasis, CLINIC (782)

Leishmaniasis, detail:
Leishmaniasis, CLINIC (783)

Leishmaniasis, cheek:
Leishmaniasis, cheek, CLINIC (4178)

Further examples of leishmaniasis:

Histology:

Mixed infiltration with lymphocytes, plasmocytes, pale and epitheloid macrophages, some of them containing fine granules within their cytoplasm. Microorganisms (2 µm Leishman-Donovan bodies) are found within macrophages and free in the tissue. Giemsa staining is helpful.

5.14.5.2  Demodecidosis

Introduction:

Pathogenic role of the mite Demodex folliculorum is doubted, some patients with massive infestation may benefit from antiparasitic therapy. (See 1, 2, 3 too).

5.14.5.3  Scabies

Etiology:

Caused by the mite Sarcoptes scabiei

Clinical signs:

  • location: wrists, web spaces between the fingers, palmar and lateral aspects of the fingers, areola mamme, penis, trunk
  • tiny papules, excoriations, burrows, pustules
  • eczematization and impetinization
  • nodular form affects the genital, esp. in childres
  • palms, soles, scalp and face is affected in immunocompromised patients and children
  • severe pruritus with maximmum at night
  • sometimes residual postscabietic nodule is formed

Histology:

Scabies mite creates subcorneal burrows, where parts of larvae, eggs or feces can be found. Sometimes only undulated epidermal surface (imprint of the parazite) can be found. Dermal reaction varies, eosinophils are often present, sometimes vasculitis, epidermis is thickened, sometimes with spongiosis.

In postscabietic nodules no parazites are to be found.

5.14.5.4  Larva migrans

Etiology:

Larvae of the dog or cat hookworm: Ancylostoma caninum

Clinical signs:

  • characteristic 2 mm wide burrow
  • migrates several mm/day
  • spontaneous regression

Histology:

Spongiosis, intraepidermal spongiotic vesicles, necrotic keratinocytes, eosinophils. The larva itself is difficult to catch (is several milimeters ahead of the eruption).

5.14.5.5  Myiasis

Clinical signs:

  • caused by flies laying their eggs into the skin
  • sometimes in debilitated persons
  • Tumbu fly (Cordylobia anthropophaga) and others (tropical Africa)
  • larve develop within the dermis and subcutis
  • itching and painful sinuses with purulent discharge
  • lesions heal after extraction of the larvae (+ ev. antibiotics)
5.14.5.6  Tungiasis

Clinical signs:

  • skin infestation by the flea Tunga penetrans
  • tunga is feeding on mammals
  • Caribbean region, Africa, India, Pakistan, and Latin America
  • female gets into the dermis and gets enlarged, breathes through a small skin opening
  • eggs came out through the skin opening
  • after laying the eggs the female dies and is eliminated
  • pruritic and painful nodules and ulcers
  • localization: legs (interdigital regions)
  • secondary inflammation and phlegmone may complicate the disease

Histology:

Intradermally located female flea, size up to 10 mm, with eggs within the body cavity. The fly is surrounded by inflammation.

5.14.5.7  Pediculosis capitis

Clinical signs:

  • Pediculus capitis is the parasite of the hair (ova, parazite)
  • excoriations, eczematization, impetiginization
  • severe pruritus
5.14.5.8  Pediculosis pubis

Introduction:

Pediculosis pubis is caused by the louse Pediculus phtirius.

5.14.5.10  Cheyletielosis

Etiology:

  • mite, living on the skin of dogs, cats and other animals
  • can be transmitted to human

Clinical signs:

  • pruritic red papules on the trunk and extremities
  • usually disappears after several weeks

Histology:

Mite or its eggs can be identified in the skin surface scrappins.

Pictures

Cheyletielosis, parazite, nativ:
Cheyletiella, nativ 20x (6100)

Cheyletiella, nativ 40x (6101)

5.14.6  Insect bite reaction

Clinical signs:

  • papules, vesicles, later sometimes pustules
  • variable edema
  • itching, pain

Histology:

Histology variable, usually superficial and deep inflammatory infiltrate of variable density, maximal in the site of injury, usually containing many eosinophils. The site of the bite is often centered on a follicle. Sometimes remnants of insect can be found. Vasculitis is sometimes present. History, season and other information can help in diagnosis.

5.14.6.2  Trombicula autumnalis, Harvest mite

Etiology:

Eggs are laid in spring, larvae hatch after about two months, then wait in low vegetation. After attaching to (thin) skin of people or warm blooded animals they release digesting saliva and suck the digested tissue. They fall of after 4 days and finish their development cycle.

Clinical signs:

  • larva attaches the skin, often near the follicle
  • small papules and pustules are formed, strong pruritus
  • excoriations are common
  • after stay in nature, especially in warm weather

Histology:

Slight inflammation, necrosis of the tissue near the attachment.

Pictures

Tiny parazite within the follicular ostium, probably trombicula:
Insect bite reaction, HE 40x (4994)
  [zoomify]
Insect bite reaction, HE 40x (4995)
  [zoomify]
Insect bite reaction, HE 40x (4996)

5.14.6.3  Bat bite reaction

Introduction:

Case of widespread reaction to bat bite in a biologist with formation of livid papules. Rabies infection was not present.

5.14.7  Hand, foot and mouth disease

Etiology:

Causes by Coxsackie virus (Picornavirus).

Clinical signs:

  • affects children
  • small epidemies

Histology:

Intraepidermal vesicles caused by baloon and reticular degeneration. The inflammatory infiltrate consists of lymphocytes at first, later neutrofils appear as well.

Pictures

Hand foot and mouth disease:
Viral exanthema, HE 20x (4442)

Hand foot and mouth disease:
Hand foot mouth disease, HE 20x (4509)

Hand foot and mouth disease:
Hand foot mouth disease, HE 20x (4510)

Hand foot mouth disease:
Hand foot mouth disease, HE 60x (6428)

Hand foot mouth disease, HE 60x (6429)

5.14.8  Gianotti Crosti syndrome

Clinical signs:

  • papules, erythema
  • location: limbs, face
  • lasts about 3 weeks, does not recurr
  • accompanies sometimes B hepatitis (or other viroses)

Histology:

Lichenoid infiltrate, spongiosis, perivascular lymphocytic infiltration, edema and sometimes extravasation of erythrocytes.

Pictures

Gianotti Crosti syndrome:
Gianotti-Crosti syndrome, HE 20x (4264)



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