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Changes caused by rubbing, scratching and pressure

5  Non-tumorous skin diseases

5.3  Changes caused by rubbing, scratching and pressure

5.3.1  Lichen simplex

Etiology:

Caused by long lasting rubbing and scratching of the pruritic skin. The original cause for the pruritus usually cannot be determined (can be caused by psychiatric disturbance as well).

Clinical signs:

  • main units:
    • prurigo simplex (strophulus)
    • prurigo subacuta et chronica (hepatica, diabetica, uremica, lymphatica, gestationis etc.)
    • prurigo nodularis of Hyde
  • symetrical lesions on the extremities, upper back
  • neck, arms, legs (esp. sites within reach of the patient)
  • urticarial papules, seropapules, nodules, excoriations, pigment changes, atrophic scars
  • severe pruritus
  • prolonged course

Pictures

Prurigo chronica with depigmented scars:
Prurigo, CLINIC (1099)

Further examples of prurigo simplex:

Histology:

Hyperkeratosis (usually without parakeratosis), acanthosis, hypergranulosis, fibrosis and increased number of dilated capillaries of the upper corium. Practically no spongiosis, infiltrate none or slight. Sometimes excoriations are found, sometimes only tiny subepidermal deposits of fibrin. In such lesions exocytosis and parakeratosis can be present.

5.3.1.1  Strophulus

Clinical signs:

  • repeated crops of small pruriginous vesicles on urticarial background
  • affects usually children (and sometimes adolescents)
  • lesions are often excoriated

Histology:

Variable acanthosis, spongiosis, spongiotic vesicles. Often excoriated.

5.3.1.2  Prurigo gestationis

Clinical signs:

  • appears at the end of the first trimester
  • resolves after delivery
  • acral pruritic papules

Histology:

Unspecific: lymphocytic perivascular infiltrate, acanthosis, parakeratosis, excoriations.

Pictures

Prurigo gestationis:
Prurigo gestationis, HE 60x (14017)

5.3.2  Prurigo nodularis

Etiology:

  • chronic dermatitis of similar etiology as lichen simplex chronicus; changes are more prominent.
  • pruritic nodules which are continuously scratched by the patient

Pictures

Prurigo nodularis:
Prurigo, CLINIC (1100)

Prurigo nodularis:
Prurigo, CLINIC (1101)

Examples of psychogenic pruritus:

Histology:

Hyperkeratosis, prominent acanthosis (longer in the center of the lesion), hypergranulosis, superficial dermal fibrosis.

5.3.3  Prurigo senilis

Clinical signs:

Affects elder persons, the picture is similar to that in lichen simplex.

5.3.4  Atopic dermatitis

Pathogenesis:

Changes caused by scratching accompany atopic dermatitis.

5.3.5  Picker's nodule

Clinical signs:

  • repeated scratching or picking of the skin
  • patients often do not scratch consciously
  • sometimes in patients with psychiatric history (depression, obsessive etc.)

Histology:

Prominent acanthosis, hyperkeratosis, thickened granular layer. Crusts, erosions. The apperance corresponds to prurigo nodularis.

Pictures

Picker's nodule:
Picker's nodule, HE 20x (5232)

5.3.6  Excoriation

Clinical signs:

  • occurs in pruritic dermatoses (eg. dermatitis herpetiformis, atopic eczema, lichen ruber, Grover's disease) or prurigo (simplex, senilis, nodularis, neurotica)
  • scratches in various stages of healing
  • occurs especially on sites patient can reach easily

Histology:

Epidermal defect, covered by crust with fibrin and neutrophils; variable dermal infiltrate, usually superficial. In healing lesions epidermis regenerates.

Pictures

Excoriation, reason unknown:
Excoriation, HE 40x (5497)

Excoriation:
Excoriation, HE 40x (2036)

Another case:
Excoriation, HE 40x (2389)

Exkoriation, eczem dermatitis:
Excoriation (eczem dermatitis), HE 40x (2665)

5.3.7  Chronic pressure (hip)

Histology:

Chronic pressure can cause similar changes like rubbing (hyperkeratosis, hypergranulosis).

5.3.8  Amputation stump

Clinical signs:

In amputation stumps changes caused by chronic pressure may develop as well. In addition there is increased number of blood vessels and degenerative changes of the corium.

Pictures

Amputation stump, thigh:
Amputation stump, HE 20x (3471)

5.3.9  Granuloma fissuratum

Clinical signs:

  • location: face (pressure caused by spectacles) or oral mucosa (pressure by dental prosthesis)
  • papule or nodule, often with central depression
  • sometimes ulcerated

Histology:

Papule with central depression, with hyperkeratosis and parakeratosis, sometimes ulcerated. Acanthosis, variable dermal edema and/or fibrosis. Variable chronic dermal inflammation.

Pictures

Granuloma (acanthoma) fissuratum:
Acanthoma fissuratum, HE 20x (4377)

5.3.10  Pressure necrosis

Clinical signs:

  • pressure sores (decubitus ulcers) occur in immobilized patients due to chronic pressure in tissues overlying bony prominences. The lumbosacral region, greater trochanters and heels are the most often affected areas. Tissue ischemia and neural damage lead to necrosis.
    I. degree — erythema
    II. degree — induration,blisters
    III. degree — shallow ulcers,
    IV. degree — deep necrosis of fat and muscle
    V. degree — bone destruction
    Underlying a small skin defect there can be vast necrosis of deep tissues and proliferation of granulation tissue.

Pictures

Decubitus of the heel:
Pressure necrosis, decubitus, heel, CLINIC (5567)

Examples of decubital ulcerations:

Histology:

Epidermal necrosis, subepidermal bulla, vascular proliferations, often secondary inflammation.

5.3.11  Tyloma, callus

Clinical signs:

  • tyloma is caused by chronic external pressure
  • clavus is caused by combination of internal prominence and external pressure

Histology:

Prominent hyperkeratosis, tyloma is usually without parakeratosis, clavus has a parakeratotic column in the centre.

5.3.12  Clavus

Clinical signs:

  • hyperkeratotic lesion caused by chronic pressure at the sites of bony prominences

Histology:

Prominent hyperkeratosis with parakeratosis, epidermis is centrally atrophic, on the periphery acanthotic.

Pictures

Calcifying cartilaginous exostosis with reactive epidermal changes:
Calcifying exostosis, HE 20x (4791)  [zoomify]

Calcifying cartilaginous exostosis with ulceration and reactive epidermal changes:
Cartilaginous exostosis, HE 40x (5385)

Cartilaginous exostosis with ulceration:
Ulcerating exostosis, HE 40x (6206)

Subungual exostosis:
Subungual exostosis, HE 20x (5004)  [zoomify]

5.3.13  Morsicatio buccarum

Etiology:

Caused by habitual chewing of buccal mucosa.

Histology:

Uneven surface, bacteria, hyperkeratosis, parakeratosis, acanthosis.


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