Chik Sign: A Clinical Clue to Chikungunya Infection- A Case Series

Abstract

Chikungunya, transmitted by Aedes mosquitoes, manifests with fever, joint pain, and a distinctive cutaneous feature known as the “Chik sign” or “Brownie nose.” The Chik sign is an asymptomatic freckled hyperpigmentation of the tip and ala of the nose and may persist in the post-infective period. This nasal pigmentation can aid in diagnosing this viral infection, especially in resourcepoor settings where serological confirmation is not feasible. Pigmentary changes, though asymptomatic, can persist for months and can be managed conservatively with sun protection, topical moisturisers, and depigmenting creams. The present case series describes three patients with nasal pigmentation that developed after an episode of chikungunya fever. The first patient was a one-month-old female neonate who developed fever at 15 days of age, followed by nasal hyperpigmentation, with a positive maternal history of chikungunya. The second case was a 29-year-old female patient, who developed fever and joint pain, followed by nasal hyperpigmentation one week later, and was diagnosed as a case of chikungunya based on clinical and serological evidence. The third case involved a 62-year-old male patient, who developed fever and joint pain two months ago, followed by nasal hyperpigmentation one week later, and was diagnosed as a case of chikungunya based on clinical and serological evidence.