Dermatitis cruris pustulosa et atrophicans

Clarke GH (Nigeria), 1952

Chronic inflammatory dermatosis of the distal extremities with disseminated follicular pustules, keratotic papules, shiny atrophic skin and corneolytic scaling, which occurs almost exclusively in the tropics and is common there but has been little researched. It leads to follicular atrophy with alopecia in the affected areas.

Sugathan et al. made the following clinical classification, with overlap of multiple stages being common:

• Grade 1: Follicular pustules only....
• Grade 2: Follicular pustules and papules with broken hairs, perifollicular crusts, and scale ruffles. Incipient alopecia.
• Grade 3: Few peripheral pustules, infiltrated keratotic papules on atrophic shiny skin. Marked alopecia.
• Grade 4: Complete hair loss. Atrophic-glossy skin with fine scaling. No pustules, some discrete papules in the periphery.

DCPA occurs in hot and humid climates (sub-Saharan Africa, India, Malaysia, and Indonesia), prevalence up to 5%. Occluding fats and oils used for skin care (e.g., petroleum jelly preparations, coconut oil), oil-soaked clothing (e.g., auto mechanics, cooks), occluding synthetic fiber clothing, work in humid environments (e.g., rice fields, fishermen) appear to be critical pathogenetic factors. Staphylococcus aureus can be regularly isolated from the pustules.

Especially in otherwise healthy young adults (from puberty to about 30 years of age). Case series from India show a clear preference of the male sex, those from Africa m:w = 1:1. In Uganda, according to own experience, mainly young women are affected.

Lower leg extensor sides, rarely additionally calves, rarely forearm extensor sides and gluteal. Always symmetrical. Backs of feet and hands left out.

Disseminated follicular pustules with surrounding edema/erythema, shiny skin surface with loss of skin patches and craquelé-like scaling, in the further course atrophic alopecia with loss of follicles. Frequently severe pruritus, but also asymptomatic courses.

In early stages, intraepidermal and subcorneal pustules in the epidermal region of the follicles, polymorphous perifollicular infiltrate (neutrophils, lymphocytes, possibly eosinophils and plasma cells). Focal perivascular round cell infiltrates in the upper dermis. In the atrophic stage: atrophy of the epidermis, loss of skin appendages and fibrosis of the upper dermis (scarring final stage) .

Distinct clinical picture, smear (with evidence of bacteria) if necessary, histology.

• Superficial folliculitis
• Tinea cruris
• Keratosis follicularis
• Adult form of eosinophilic pustular folliculitis
• Impetiginized scabies
• Exsiccation dermatitis (grade 4 only)

Avoidance of provocation factors is the basis of any therapy! No oils, no fatty ointments, no petroleum jelly. Air-permeable loose cotton clothing. Urea lotions (O/W) for care.

Antiseptic lotions (e.g., Vioform 2% in Lotio alba), benzoyl peroxide gel 5%, clioquinol cream 0.5%, clindamycin gel, nadifloxacin gel, also in combination.

Isolated reports of positive effects of local PUVA therapy.

Antibiotic therapy for 14 days, as initial therapy: doxycycline 100 mg/day, minocycline 50-100 mg/day, flucloxacillin 3x1g/day, cotrimoxazole 2x daily.

Even with adequate therapy and avoidance of the provoking factors, the course is often protracted and chronically recurrent over several years.

1. Joao AL, Cunha N, Pinheiro RR, Lencastre A (2022) Dermatitis Cruris Pustulosa et Atrophicans: Scarring Alopecia Beyond Scalp Hair. Skin Appendage Disord 8: 280-286.
2. Saranya TM, Sasidharanpillai S, Govindan A (2021) Histopathology features in dermatitis cruris pustulosa et atrophicans. Journal of Skin and Sexually Transmitted Diseases 3: 195-198.
3. Iraba JB (2019) A clinical and epidemiological study of dermatitis cruris pustulosa et atrophicans in Northern Tanzania. Abstract, 24 world congress of dermatology, Milan 2019.
4. Kaimal S, D'Souza M, Kumari R (2009) Dermatitis cruris pustulosa et atrophicans. Indian J Dermatol Venereol Leprol 75: 349-355.
5. Sugathan P, Jacob Z, Joy MI (1973) Folliculitis cruris pustulosa et atrophicans. Indian J Dermatol Venereol Leprol 39: 35-40.
6. Harman RRM (1968) Dermatitis cruris pustulosa et atrophicans, the Nigerian Shin disease. British Journal of Dermatology 80: 97-107.