Annular leucocytoclastic vasculitis

[Annular leukocytoclastic vasculitis: A particular form of small vessel vasculitis?]

BACKGROUND

Leukocytoclastic vasculitis is characterized by necrotizing inflammation around small blood vessels, composed mainly of neutrophils. Skin lesions in leukocytoclastic vasculitis are polymorphous, but a rare annular variant exists of which dermatologists must be aware. Herein we present a new case of this entity.

PATIENTS AND METHODS

We report the case of a 74-year-old man who developed annular purpuric infiltrated lesions mainly on the lower limbs, with leukocytoclastic vasculitis being confirmed by histology. This annular leukocytoclastic vasculitis regressed spontaneously with no recurrence after 6 months. The aetiology was not established.

DISCUSSION

Annular leukocytoclastic vasculitis is rare, and the mechanisms underlying annularity and peripheral spread as well as the aetiology remain unexplained. This form of vasculitis with unusual clinical features may constitute a new entity in the subclass of immune complex small vessel vasculitis within the Chapel Hill classification. While the aetiology and physiopathology of this vasculitis are unknown, despite the possibility of recurrence, skin involvement appears isolated and the condition carries a good prognosis.

Annular leukocytoclastic vasculitis associated with anti-tuberculosis medications: a case report

Introduction

Anti-tuberculosis drug-induced cutaneous leukocytoclastic vasculitis has been rarely reported. To the best of our knowledge, this is the first reported case of annular leukocytoclastic vasculitis associated with anti-tuberculosis drug administration.

Case presentation

We report a case of annular leukocytoclastic vasculitis induced by anti-tuberculosis medication. A 62-year-old Thai man presented to our facility with a generalized exanthematous rash on his trunk and extremities that resolved shortly afterwards. Subsequently, he developed multiple, erythematous-to-purplish, non-blanchable macules and papules with an annular arrangement on his extremities. The skin rash occurred after two weeks of anti-tuberculosis medication. The histopathology of the purpuric skin lesion was consistent with leukocytoclastic vasculitis. The skin lesion improved after discontinuation of the anti-tuberculosis drugs and treatment with oral antihistamine and topical corticosteroid drugs. Streptomycin, ethambutol and ofloxacin were administered as second-line anti-tuberculosis therapy during his hospitalization. No adverse reactions were observed.

Conclusions

Leukocytoclastic vasculitis should be considered in the differential diagnosis of annular non-blanchable macules and papules. Although rare, anti-tuberculosis drugs should be considered potential causes of drug-induced annular leukocytoclastic vasculitis.