Marginal acrokeratoderma and psoriasis: is there an association?

Case 1  A 70‐year‐old housewife presented to us with multiple, asymptomatic, depressed, crateriform plaque lesions over the radial margin of the index finger and thumb and thenar and hypothenar eminences of both hands of 25 years' duration ( Fig. 1). There was no history of prolonged sun exposure or repeated trauma to the hands and there were no such lesions on the soles. None of her other family members were affected. We made a provisional diagnosis of keratoelastoidosis marginalis. Skin biopsy revealed an unremarkable epidermis, with minimal lymphocytic infiltration in the upper dermis and hyalinization in the reticular dermis, extending to the deeper dermis. Two years later she returned with well‐defined, erythematous, scaly, mildly itchy plaque lesions over the instep of both feet and the center of both palms. A clinical diagnosis of palmoplantar psoriasis was made. 1Case 1. Crateriform plaque lesions on the hands. Note the palmoplantar psoriasis A careful search to discover any correlation between these two disorders revealed that plaque lesions with a central saucer‐like depression on the sides of the fingers and the palmar surface have been noted in patients with otherwise typical lesions of psoriasis (Caro MR, Senear FE. Psoriasis of the hands. Nonpustular type. AMA. Arch Dermatol Syphilol 1956; 74: 629‐633). We then began to look for these lesions in all patients attending our dermatology clinic. Screening of more than 500 patients suffering from cutaneous disorders other than psoriasis revealed no marginal keratodermas. A careful search of 500 consecutive patients attending our psoriasis clinic revealed two more cases. Case 2  A 23‐year‐old laboratory technician with psoriasis over the center of the palms of 6 months' duration was found to have multiple depressed plaques of 3 × 3 mm along the outer margin of the index finger and inner margin of the thumb on examination ( Fig. 2). These had been present before the appearance of classical psoriasis lesions, but the exact duration was not known. 2Case 2. Depressed plaques along the outer margin of the index fingerCase 3  A 62‐year‐old shopkeeper with generalized psoriasis of 2 years' duration was found to have pin‐head to pea‐sized asymptomatic depressed lesions over the margins of the index finger and thumb ( Fig. 3). He was worried about them mainly due to their cosmetic appearance. None of the above patients had any gross evidence of actinic damage. All the lesions were crateriform, with no elevated or translucent lesions seen. 3Case 3. Depressed lesions on the index finger. Note the lesions of psoriasis over the dorsa of the hands