Reactive granulomatous dermatitis as a histological pattern including manifestations of interstitial granulomatous dermatitis and palisaded neutrophilic and granulomatous dermatitis: a study of 52 patients.

BACKGROUND: Confusion exists regarding interstitial granulomatous dermatitis (IGD) and palisaded neutrophilic and granulomatous dermatitis (PNGD). OBJECTIVE: To determine whether IGD and PNGD are two different entities, or whether they must be considered as two subtypes of the same reactive pattern, and thus whether the unification of the nomenclature is necessary. METHODS: Observational retrospective multicentre study of patients with IGD and PNGD evaluated between 1999 and 2019 and review of their clinical and histological features. RESULTS: We identified 52 patients (38 women and 14 men). Clinical and histological findings of IGD were observed in 88.4% of cases. The most common cutaneous lesions were plaques/macules (IGD) or annular plaques and papules/nodules (PNGD), located mostly on the limbs and trunk. The rope sign was developed in two patients with IGD that associated autoimmune disorders. Similar associated comorbidities (75%) were found in both entities, mainly autoimmune diseases (53.8%). In IGD, the infiltrate was predominantly lympho-histiocytic. Neutrophilic infiltrates, karyorrhexis and skin lesions with limited clinical course were mainly associated with PNGD biopsies. In biopsies with a limited recurrent course, a predominant lymphocytic inflammatory infiltrate was found. Collagen degeneration was present in 75.9% of cases. The floating sign was observed only in IGD type patients (63%). Overlapping histological findings were found in one fourth of cases, especially between IGD and interstitial granuloma annulare. Interface dermatitis, apparently unrelated to drug intake, was observed in 4 cases of IGD. CONCLUSION: We support the term reactive granulomatous dermatitis to unify both the clinical and histological findings of IGD and PNGD, and the overlapping between IGD and interstitial granuloma annulare. According to this, a spectrum of histological changes will be found depending on the clinical course of the skin lesions.

Mucocutaneous manifestations of cocaine abuse: a review.

Cocaine is an alkaloid extracted from the leaves of the Erythroxylum coca plant that emerged in the 1970s as a fashionable drug among members of certain social backgrounds. Cocaine abuse is a problem of current interest, which is mostly hidden and underdiagnosed, but dramatically widespread among all socio-economic strata, and with an incidence which is increasing at an alarming rate. There are 1.5 million cocaine consumers in the USA. In Spain, the prevalence of consumption among the population between 15 and 65 years old is higher, reaching 3.1%. Because of this, it seems important to understand and recognize all the mucocutaneous manifestations of cocaine abuse which have been reported in the literature to clarify and to help dermatologists in their daily practice. In this article, we describe the principal mucocutaneous manifestations of cocaine abuse and we review isolated case reports which have been published in the literature. Because the dermatologist may deal with an unknown problem as well as with an already well-known history of cocaine abuse, it seems logical to separate the mucocutaneous manifestations into those which are frequent and highly suggestive, such as those caused by vascular injury, damage to mucosal membranes, infectious diseases or neutrophilic dermatosis, especially when suffered by young people and in consonance with other systemic manifestations and, those which have been reported in the literature as isolated case reports. We also summarize the main aspects of its pathogeny, principal pharmacodynamic and pharmacokinetic characteristics, and diagnostic tools.