Figurate erythema in 11 Eastern European sphynx cats

BACKGROUND

In humans, figurate erythema (FE) represents a heterogenous group of dermatoses with circular or serpiginous erythematous skin lesions; FE has not been reported in cats.

OBJECTIVES

To report clinical and histological characteristics and outcomes of FE in sphynx cats from Baltic sea-bordering countries.

ANIMALS

Eleven client-owned sphynx cats with FE.

MATERIALS AND METHODS

We recruited cases meeting the following criteria: (i) a sphynx breed, (ii) FE with or without scaling, (iii) a chronic, waxing-and-waning course lasting longer than a month and (iv) an absence of other skin diseases.

RESULTS

Of 11 cats, there were seven Donskoys, one Peterbald, one Ukrainian Levkoy and two presumed Canadian sphynxes; all except one were males, and the age of onset was <12 months in eight cats. Skin lesions lasted between 1.2 and 56 months, and they consisted of erythematous plaques with a linear-to-serpiginous, annular, gyrate or iris configuration predominating on the trunk and extremities. Scaling was often seen trailing the edge of the centrifugally expanding erythema. All cats were otherwise asymptomatic or mildly pruritic. Dermatophytosis was ruled out by special stains and/or fungal cultures in eight cats. Microscopic lesions revealed focal, mild-to-moderate epidermal hyperplasia and hyperkeratosis, minimal-to-mild dysplasia and subepidermal collagen smudging. Special stains were negative for dermatophytes. The clinical remission of FE was not achieved with diet changes or medical interventions; yet, a spontaneous, transient, partial or complete improvement occurred in most cats.

CONCLUSION AND CLINICAL RELEVANCE

This is the first report of FE in sphynx cats from Eastern Europe.

Annular Erythemas and Purpuras

Annular dermatoses are a heterogeneous and extremely diverse group of skin diseases, which share in common annular, ring-like patterns with centrifugal spreading. Numerous skin diseases can sometimes display annular lesions, but some specific skin conditions are originally annular. We take the opportunity to review here mainly the causes of primary annular erythemas and their differential diagnoses, but also the rare causes of annular purpuras.

Neonatal lupus erythematosus presenting as a non-bullous histiocytoid neutrophilic dermatosis

Histopathologic findings in neonatal lupus erythematosus (NLE) are usually congruent with those of subacute cutaneous lupus erythematosus. However, neutrophilic dermatosis-type histopathologic features are being increasingly recognized in the literature including rare cases with variant histiocytoid morphology. We report the case of a 7-week-old male presenting with figurate erythema. His mother was found to have elevated anti-nuclear antibodies and was positive for anti-SSA/Ro, anti-SSB/La antibodies and Ro52 autoantibodies. The infant had a similar serological profile. Skin biopsy showed a histiocytoid interstitial infiltrate with mild lichenoid features, sparse neutrophils and mild leukocytoclasis. The histiocytoid infiltrate showed prominent CD68, CD163, and myeloperoxidase expression. Isolated clusters of CD123⁺ histiocytes were also present. This case highlights the rare finding of non-bullous neutrophilic dermatosis with histiocytoid change in neonatal lupus. In neonates presenting with figurate erythemas with morphological histiocytic change on biopsy, NLE should be considered as a differential diagnosis and investigated for accordingly.

Generalized pustular figurate erythema: A newly delineated severe cutaneous drug reaction linked with hydroxychloroquine

A severe cutaneous drug reaction resembling acute generalized exanthematous pustulosis resulting from ingestion of hydroxychloroquine has been documented. It is distinguishable by its longer incubation period, more varied morphology with initially urticarial and later targetoid and arcuate plaques, recalcitrance to therapy and longer duration. Given the anticipated surge in the use of hydroxychloroquine due to its reported benefits in those with coronavirus disease 2019, specific recognition of this entity is pivotal. We delineate it as generalized pustular figurate erythema.