Erosive pustular dermatosis (chronic atrophic dermatosis of the scalp and extremities)

Figures & data

Figure 1 (A–C) Chronic eosinophilic dermatosis of the scalp in a 76 year-old male. (A) Overview. (B) Detail of crusted and erosive lesion with overgranulation. No signs of reepithelialization. (C) Excision and split-skin transplant. Ten days after transplantation, a stable transplant without recurrence is seen.

Table 1 Differential diagnosis of erosive pustular dermatitis of the scalp (EPDS)

Neonatal cephalic pustulosis	Only in neonates, Malassezia furfur present, sebaceous gland hyperplasia, usually neither crusts nor epidermal atrophy
Kerion celsi	Not much inflammation but severe destruction of hair follicles; pustules, oozing lesions possible; potassium hydrochloride-stained scales or hairs for microscopy, fungal culture
Subcorneal pustular dermatosis	Some authors suggest a closer relationship to EPDS, not restricted to the scalp, blisters, hypopyon
Autoimmune bullous diseases	Direct immunofluorescence and autoantibody screening are helpful; histopathology shows intra- or subepidermal blistering; among these disorders, pemphigus vegetans comes closest clinically
Lichen planus of the scalp	Cicatrical alopecia with follicular papules, hyperkeratotic collars around the hair shafts; histology shows lymphocytic infiltrates perifollicular and along the dermoepidermal junction, hypergranulosis
Chronic discoid lupus erythematosus	Cicatrical alopecia; epidermal vacuolar basal cell degeneration and atrophy; dermal mucin deposits; lymphocytic infiltrate, immunoglobulin G and C3 deposits along the dermoepidermal junction
Folliculitis decalvans	Follicular papules and pustules, Staphylococcus aureus present; paint brush sign of bundles of residual hair, neutrophilic infiltrate
Dissecting folliculitis	Deep folliculitis with follicular destruction; subcutaneous liquefaction, oozing; later keloid formation, can be associated with inverse acne (hidradenitis suppurativa)
Chronic vegetating pyoderma	Often in patients with impaired immune function; dermal abscesses due to staphylococci and/or streptococci
Superficial granulomatous pyoderma	Slowly spreading superficial ulcerations, elevated enrolled border; histopathology is uncharacteristic with neutrophils, vasculitis, vascular fibrin deposits, or thrombosis of small vessels
Field cancerization	Epidermal atrophy, chronic sun damage; multiple actinic keratoses, and in advanced cases squamous cell carcinoma are present; histopathology is most helpful

Figure 2 A 57-year-old patient with chronic actinic damage, multiple actinic keratoses and a T2 squamous cell carcinoma on the scalp. Field cancerization is an important differential diagnosis to erosive pustular dermatosis of the scalp.

Table 2 Therapeutic opportunities in erosive pustular dermatosis of scalp and leg

Treatment	Scalp	Leg
First-line therapy	High-potency topical corticosteroids	High-potency topical corticosteroids
	Topical calcineurin inhibitors	Topical calcineurin inhibitors
Second-line therapy	Oral corticosteroids	Topical calcipotriol
	Topical calcipotriol
Third-line therapy	Oral acitretin	Dapsone gel