Ans. (c) ChikungunyaRef: Illustrated Synopsis of Dermatology and SexuallyTransmitted Diseases by Neena Khanna 4th Ed; Page No- 284* Melasma is most commonly occurs in female with peak incidence 30-50 years. In Melasma brown macular lesions with scalloped margins are seen on the cheeks and nose. So it is ruled out.. Melasma1. sites of predilection of melasma2 (1) Melasma; (2) Sites of predilection of Melasma* As the patient has previous history of taking drugs so fixed drug eruption may the answer but In fixed drug eruption; lesions recur at the same site, each time the drug is taken,usually 8-16 h after the intake of drug and the lesions are seen in genitalis and lips. So it is ruled out.* In this case the rash presents in tipoff the nose with chicks and chick signs are marked. So it is case of Chikungunya.Chikungunya Virus* Chikungunya is mosquito-borne viral disease first described during an outbreak in southern Tanzania.* It is a RNA virus that belongs to the Alphavirus genus of the family Togoviridae.* Vector is Aedes aegypti.* No animal reservoir.* Clinical Features:# Typical biphasic fever# Crippling joint pain with maculopapular rash# Conjunctivitis# Lymphadenopathy.* Investigation:# IgM antibody levels are highest 3 to 5 weeks after the onset of illness and persist for about 2 months.# IgM/IgG ELISA in paired sea# RTPCR* Treatment:# No vaccine is available# No specific antiviral drugs# Supportive measures like antipyretics, analgesics and fluids.