A 20 year old woman with past history of enteric fever 4 months back presents with diffuse hair loss for 1 month. The likely cause is:

Ans: B (Telogen effluvium) Ref: Disorders of hair and nails. In: Thappa DM. editor. Essentials in Dermatology, 2nd'edn., New Delhi: Jay pee brothers medical publishers (P) Ltd 2009; 189-97.Explanation:Telogen effluvium (Diffuse)Hair follicles enter telogen phase and shed 6-10 weeksOccurs after a precipitating event like parturition, high fever, surgery, stress and drugs like OCP. beta blockers, ACEAlopecia areata (Patchy)Autoimmune disorderExclamation mark hairs (broken short hairs with proximal tapering) which are dystrophic anagen hairs are characteristic - Patchy hair lossAndrogenetic alopecia (Diffuse)Terminal to vellus hair transformationFrontal hairline recession and thinning over vertex in malesDiffuse thinning more so in vertex in femalesAnagen effluvium (Diffuse)Abrupt cessation of hair growth in anagen phase and shed due toCytotoxic drugs like cyclophosphamide, doxorubicin, nitrosureas, heparin, warfarin, vitamin A. INH.