IDIOPATHIC PERNIOSIS AND ITS MIMICS - A CLINICAL AND HISTOLOGICAL STUDY OF 38 CASES

Perniosis is a term applied to cold-induced painful or pruritic erythe matous or violaceous acral papular or nodular lesions. We examined 39 skin biopsies from 38 patients who presented with acral purpuric lesio ns, suggesting a diagnosis of perniosis clinically or pathologically. The presence of a systemic or extracutaneous disease was established i n 17 patients, including 5 with systemic lupus erythematosus (SLE), 3 with antiphospholipid antibodies, in 1 in whom there was underlying HI V disease, 2 with viral hepatitis, 2 with rheumatoid arthritis (RA), 2 with cryofibrinogenemia, 1 with hypergammaglobulinemia, 1 with iritis , and 1 with Crohn's disease. In the other 21 patients, the clinical p resentations prompted further studies in 12, which showed a positive a ntinuclear antibody (ANA) in 10. A diagnosis of idiopathic perniosis ( DP) was rendered in all 21 of these patients including those in whom a positive ANA was discovered, based on the absence of any other serolo gical markers, signs, or symptoms indicative of a specific systemic di sease complex; many had Raynaud's phenomenon, small joint arthralgias, atopy, or a family history of either connective tissue disease or Ray naud's disease. The histopathology of IP comprised a superficial and d eep angiocentric lymphocytic infiltrate with papillary dermal edema an d lymphocytic exocytosis directed to retia and acrosyringia. A few cas es showed a mild vacuolopathic or lichenoid interface dermatitis, adve ntitial dermal mucinosis, lymphocytic eccrine hidradenitis, vascular e ctasia, and thrombosis confined to dermal papillae capillaries. The bi opsies from patients with iritis, RA, and Crohn's disease showed a gra nulomatous vasculitis and a granuloma annulare-like tissue reaction. T he biopsies from the patients with SLE, cryofibrinogenemia, primary an tiphospholipid antibody syndrome, and hypergammaglobulinemia shared a similar histopathology comprising an interface dermatitis, superficial and deep angiocentric and eccrinotropic lymphocytic infiltrates, vasc ular ectasia, and dermal mucinosis with prominent involvement of the e ccrine coil. Many cases did not show features of IP, namely papillary dermal edema, thrombosis of dermal papillary capillaries, and lymphocy tic exocytosis into the retia and acrosyringia. There was frequent vas cular fibrin deposition involving reticular dermal vessels. The latter two variables were statistically significant discriminators between I P and in perniotic lesions observed in the setting of underlying syste mic disease. With respect to the latter, some cases occurred in the se tting of cold exposure and were designated by us as ''secondary pernio sis'' (SP), whereas others showed no specific association with cold ex posure and were designated as perniotic mimics (PMs) based exclusively on the gross and microscopic morphology of the lesions. Copyright (C) 1997 by W.B. Saunders Company.