Cutaneous manifestations of chikungunya during a recent epidemic in Calicut, north Kerala, south India

Background: There was a recent epidemic of chikungunya (CKG) in Calicut and other northern districts of Kerala, South India, affecting thousands of people.
Aims: To study the cutaneous manifestations of CKG and to have a serological and histopathological correlation.
Methods: A total of 162 patients (63 males and 99 females) with cutaneous manifestations of CKG were enrolled in the study and serological confirmation was done with capture IgM ELISA for CKG. Skin biopsy was done in all representative cases.
Results: Cutaneous manifestations were found more in females. There were 23 children, the youngest being 39 days old. Generalized erythematous macular rash was the most common finding. Vesicles and bullae were also common especially in infants. Localized erythema of the nose and pinnae, erythema and swelling of the pre existing scars and striae and toxic epidermal necrolysis-like lesions sparing mucosae were the other interesting findings. Different types of pigmentation were observed with a striking nose pigmentation in a large number of patients, by looking at which even a retrospective diagnosis of CKG could be made. Hence we suggest this peculiar pigmentation may be called "chik sign". There was flare up of existing dermatoses like psoriasis, lichen planus and unmasking of Hansen′s disease with type 1 reaction. Serological tests were positive in 97%. Some hitherto unreported histopathologic findings like melanophages in the erythematous rashes were observed.
Conclusion: A spectrum of cutaneous manifestations of CKG with a wide variety of unusual presentations with confirmed serological and histopathological evidence was encountered.

Keywords
Chikungunya, cutaneous manifestations, "Chik sign", IgM capture ELISA, histopathology