A 45-year-old moderately obese man presents with a rash affecting both axillae. The eruption has been present for months and on occasion either itches or burns. A 2-week course of oral fluconazole, followed by a steroid dose pack, resulted in minimal improvement. He is currently applying hydrocortisone cream. Examination reveals well-demarcated erythematous patches of the axillae. An erythematous patch with scale is also noted on his scalp.
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Inverse psoriasis is characterized by erythematous, well-demarcated patches that occur within the axillae, groin, and inframammary areas, as opposed to classic sites of involvement of psoriasis vulgaris; namely, the extremities and trunk.1 Location, rather than histology, separate the 2 entities as there are no distinguishing features when viewed microscopically. Inverse psoriasis can coexist with plaque psoriasis, and the relationship appears to be enhanced when palmar disease is present.2
The differential diagnosis for inverse psoriasis includes candidiasis, tinea infections, benign familial pemphigus, and glucagonoma syndrome. A similar clinical pattern has been reported with advanced HIV infection.3 As affected areas are prone to friction, sweating, and maceration, patients often complain of itching and burning at these sites. Treatment with topical steroid drugs of medium to high potency often leads to marked improvement,4 although short-term use is mandatory given the propensity for striae formation. Alternative therapies include topical vitamin D3 analogues and calcineurin inhibitors; biologic medications are used for refractory cases.5
Stephen Schleicher, MD, is an associate professor of medicine at the Commonwealth Medical College in Scranton, Pennsylvania, and an adjunct assistant professor of dermatology at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia. He practices dermatology in Hazleton, Pennsylvania.
- Syed ZU, Khachemoune A. Inverse psoriasis: case presentation and review. Am J Clin Dermatol. 2011;12:143-146.
- Fransson J, Storgårds K, Hammar H. Palmoplantar lesions in psoriatic patients and their relation to inverse psoriasis, tinea infection, and contact allergy. Acta Derm Venereol. 1985;65:218-223.
- Castillo RL, Racaza GZ, Roa FD. Ostraceous and inverse psoriasis with psoriatic arthritis as the presenting features of advanced HIV infection. Singapore Med J. 2014;55:e60-e63.
- van de Kerkhof PC, Murphy GM, Austad J, Ljungberg A, Cambazard F, Duvold LB. Psoriasis of the face and flexures. J Dermatolog Treat. 2007;18:351-360.
- Ješe R, Perdan-Pirkmajer K, Dolenc-Voljč M, Tomšič M. A case of inverse psoriasis successfully treated with adalimumab. Acta Dermatovenerol Alp Pannonica Adriat. 2014;23:21-23.