Subcorneal pustular dermatosis and IgA paraproteinaemia: response to both etretinate and PUVA

Abstract

A non-insulin dependent male diabetic is reported with subcorneal pustular dermatosis associated with intraepidermal IgA deposits and a benign IgA paraproteinaemia. Treatment with dapsone and etretinate was reasonably effective, but etretinate had to be discontinued due to the development of diffuse idiopathic skeletal hyperostosis. His subcorneal pustular dermatosis subsequently flared and was troublesome for 2 years until he was commenced on PUVA, with excellent response.

Subcorneal Pustular Dermatosis Treated with PUVA Therapy

“…However, in some cases, intraepidermal IgA deposits can be detected [2, 3, 4, 5, 6, 7, 9]. According to Wallach [11], SPD should be considered as ‘intraepidermal IgA pustulosis’ since this pustular dermatosis shows clinical and histopathological features identical to SPD, but with intraepidermal IgA deposits on direct immunofluorescence.…”

“…The disease may be associated with benign and malignant monoclonal gammopathies, mostly IgA [1, 2, 3, 4, 5, 6]. This relationship is probably not a coincidence in view of the rarity of both diseases [3, 4].…”

“…Differential diagnosis of SPD [1, 2, 4]includes: pustular psoriasis [1, 2, 4, 5, 12, 13], bullous impetigo [1, 2, 5, 10, 12, 13], dermatitis herpetiformis [1, 2, 10, 12, 13], pemphigus foliaceus [1, 2, 5, 12, 13], necrolytic migratory erythema [1, 2, 5], intraepidermal IgA pustulosis [11], acute generalized exanthematous pustulosis [14]and childhood chronic bullous disease [1]. …”

“…Treatments including antibiotics [9], estrogen [9], niacin [9], colchicine [2], vitamin E, corticosteroids [9], etretinate [2, 9], diaminodiphenylsulphone (dapsone) [1, 2, 9, 10], sulfapyridine [2, 10]and PUVA [2]have been proposed. However, none of these drugs has been uniformly successful.…”

“…This dermatosis may be associated with a large number of diseases such as benign and malignant monoclonal gammopathies [1, 2, 3, 4, 5, 6], colitis ulcerosa, pyoderma gangrenosum [5], leukocytoclastic vasculitis, systemic lupus erythematosus [7]and rheumatoid-like arthritis [8]. …”