<prompt> 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:Androgenic alopeciaTelogen effluviumAnageneffuviumAlopecia areata  <response>: Ans: B Telogen effluvium Ref: Disorders of hair and nails. In: Thappa DM. editor. Essentials in Dermatology, 2ndedn., New Delhi: Jay pee brothers medical publishers P Ltd 2009; 189-97.Explanation:Telogen effluvium DiffuseHair 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 PatchyAutoimmune disorderExclamation mark hairs broken short hairs with proximal tapering which are dystrophic anagen hairs are characteristic - Patchy hair lossAndrogenetic alopecia DiffuseTerminal to vellus hair transformationFrontal hairline recession and thinning over vertex in malesDiffuse thinning more so in vertex in femalesAnagen effluvium DiffuseAbrupt cessation of hair growth in anagen phase and shed due toCytotoxic drugs like cyclophosphamide, doxorubicin, nitrosureas, heparin, warfarin, vitamin A. INH. 