Skin reactions caused by phenylbutazone. Immunologic studies

Paraneoplastic pemphigoid-pemphigus? Subepidermal bullous disease with pemphigus-like direct immunofluorescence

BACKGROUND

Paraneoplastic pemphigus is a recently described variant of pemphigus, in which classic immunologic features of pemphigus are associated with subepidermal erythema multiforme-like bullae.

CASE REPORTS

Two patients with underlying malignant neoplasm had a bullous disease, which had clinical and histologic features suggestive of bullous pemphigoid while direct immunofluorescence revealed intercellular deposits of IgG and C3 throughout the malpighian layer of epidermis, a pattern usually diagnostic for pemphigus. Indirect immunofluorescence studies were negative. One mg/kg/day prednisone was enough to cure the eruption in a couple of weeks without any recurrence.

CONCLUSIONS

The disease differs from the recently reported paraneoplastic pemphigus and from other bullous diseases associating circulating pemphigus-like antibodies with clinical, histologic, and often even immunologic features of bullous pemphigoid.

Idiosyncratic reactions to antidepressants: a review of the possible mechanisms and predisposing factors

Antidepressants, a widely used group of drugs, are associated with a range of idiosyncratic reactions affecting in particular the liver, skin and both the hematological and central nervous systems. These reactions seem to be mediated by chemically reactive metabolites formed by the cytochrome P450 enzyme system, the toxicity occurring either directly or indirectly via an immune mechanism. Individual susceptibility is determined by factors, both genetic and environmental, which result in inadequate detoxication of the chemically reactive metabolite. Prevention of such reactions will depend on either the development of new compounds which are not converted to toxic metabolites or by prediction of individual susceptibility prior to drug administration.

Drug-induced anogenital cicatricial pemphigoid

A case of cicatricial pemphigoid (CP) with a rare primary localization on the mucosal surfaces of the anus and the vulva and on perianal skin, associated with long-term therapy with clonidine, is described. Direct immunofluorescence investigation of lesional skin suggests possible complement mediated tissue injury in between basement membrane and epidermal basal cells. The possibility is discussed that drug induced metabolic disturbance (cyclic AMP-system) at a local level at the site of the basal cells might lead to the formation of immunogens and be one of the initiating factors in subepidermal bullous immune dermatoses. It is concluded that in cases of cicatricial pemphigoid the use of drugs must be considered as one of the aetiological possibilities.