Purpuric macules with vesiculobullous lesions: a novel manifestation of Chikungunya.

Background: Chikungunya (CHIK) is an emerging viral disease with a myriad of cutaneous manifestations.
Aims: The aim of our study was to document the morphology and evolution of skin lesions in cases presenting with fever, purpuric macules and vesiculobullous lesions, to confirm its causative relationship with CHIK, and to investigate further in order to delineate possible mechanisms of bulla formation in these cases.
Materials and Methods: A prospective, descriptive hospital-based study was carried out at a tertiary health care centre in Kerala. A total of 10 patients were enrolled in the study and investigated.
Results: All cases had morbilliform eruption prior to onset of purpuric macules. Eight cases developed vesiculobullous lesions that arose either de novo or over a part or whole of the purpuric macules. Skin lesions resolved within an average of 7.6 days leaving post-inflammatory hypopigmentation. IgM CHIK enzyme-linked immunosorbent assay (ELISA) was positive in all 10 patients. Tzanck smear from the bullae showed lymphocytes in most cases along with acantholytic cells, necrotic keratinocytes or occasional neutrophils. Skin biopsy showed intraepidermal or subepidermal bullae. Immunohistochemistry revealed predominantly CD8 positive T lymphocytes in the infiltrate. The prognosis was good with supportive management alone.
Discussion: The clinical features in our cases are comparable to the 3 previous reports of vesiculobullous lesions in CHIK affected infants. Based on the current evidence, we hypothesize that at least 2 mechanisms are at play for these skin lesions; CHIK virus induced keratinocyte necrosis followed by a cytotoxic immune response, and possible modulation of rash by drugs.
Conclusion: With severe epidemics of CHIK spreading from Asia and Africa to the Western hemisphere, we must consider bullous CHIK as a differential diagnosis in cases with fever and purpuric and vesiculobullous lesions.
(© 2011 The International Society of Dermatology.)