Cutaneous small vessel vasculitis associated with varicella zoster infection: a case report and review of the literature.

Summary: Herpes zoster (HZ), commonly associated with large-vessel vasculitis, particularly in the central nervous system, is less frequently linked to small-vessel vasculitis. This case report presents a rare occurrence of small-vessel cutaneous leukocytoclastic vasculitis (LCV) associated with herpes zoster in an immunocompromised patient. A 73-year-old male with a recent anterior myocardial infarction, complicated by respiratory failure, was hospitalized in the ICU for an extended period. During his stay, he developed a self-limiting bullous rash that was clinically undifferentiated. Immunohistochemical and morphological analysis of a skin biopsy confirmed epidermal varicella-zoster virus (VZV) infection, alongside dermal small-vessel leukocytoclastic vasculitis, characterized by neutrophilic infiltration and vessel wall damage. This case represents the 14th documented instance of small-vessel LCV associated with VZV infection. The patient's immunocompromised state, exacerbated by his prolonged ICU stay, may have contributed to the atypical presentation, highlighting the need for clinicians to remain vigilant for such manifestations in similar populations. The occurrence of vasculitis in this context broadens the clinical spectrum of herpes zoster, emphasizing the importance of early recognition and management. This case provides valuable insight into the diverse manifestations of herpes zoster, aiding clinicians in diagnosing and managing these rare but significant complications.