Dowling-Degos disease co-presenting with Darier disease.

We present a case of a patient with long-standing hyperpigmented macules and erythematous papules over his chest, abdomen, back and arms, suggestive of Dowling-Degos disease (DDD). In addition, there were hyperkeratotic papules, alternating red and white nail-bed discolouration, and V-shaped nail notching consistent with Darier disease (DD). Histology showed findings consistent with DDD and DD on separate specimens. The lack of acantholysis in areas of filiform hyperpigmented rete ridges ruled out Galli-Galli disease (GGD). DDD results from mutations in the genes encoding keratin 5 (KRT5), protein O-glucosyltransferase 1 (POGLUT1) or protein O-fucosyltransferase 1 (POFUT1), while DD results from mutations in the ATP2A2 gene. Both genes are present on chromosome 12. In this case, the patient presented with features of both DDD and DD, which suggests that either a cooperating mutation or a mutation in an unrelated gene locus may underlie the findings in this patient.

Eruptive disseminated porokeratosis associated with corticosteroid-induced immunosuppression.

Eruptive disseminated porokeratosis (EDP) is a disease that presents clinically with sudden onset of erythematous papules and plaques, with a ridge-like border histologically represented by a cornoid lamella. We report a case of EDP occurring in a 39-year-old woman 3 days after completion of a 2-week course of oral corticosteroid therapy for an acute asthma exacerbation. The patient was treated with emollients and sun protection. Unlike the more chronic disseminated superficial (actinic) porokeratosis, EDP secondary to immunosuppression from corticosteroid therapy has very rarely been reported in the dermatological literature.

Fish-tank granuloma. The first reported case in South Africa.

The first case of infection with the non-tuberculous mycobacterium, Mycobacterium marinum, in South Africa is reported. Of special interest was the linear nodular (sporotrichoid) appearance.