02136nas a2200217   4500000000100000008004100001653001200042653001700054653002300071653001600094100001400110700001600124700001600140700001200156245007900168856008200247300001200329490000600341050001500347520155600362       2013                            d10aleprosy10ainterstitial10aGranuloma Annulare10aAllopurinol1 aSingh S K1 aManchanda K1 aBhayana A A1 aVerma A00aAllopurinol induced granuloma annulare in a patient of lepromatous leprosy  uhttp://www.jpharmacol.com/temp/JPharmacolPharmacother42152-2986587_081745.pdf  a152-1540 v4  aSINGH 20133 aGranuloma annulare (GA) is a benign, inflammatory dermatosis involving dermis or subcutis with unknown etiology and poorly understood pathology. GA has characteristic histological features of necrobiosis, granuloma formation and abundant mucin deposition. Various predisposing factors, systemic diseases and drugs have been implicated in the etiology. We hereby describe a case of 70 year old male who was a known case of lepromatous leprosy, taking multidrug therapy for 6 months presented with multiple discrete, annular, firm, non tender, smooth surfaced skin colored papular lesions ranging in size from 0.5-1 cm over back for 1 month. There was past history of intake of allopurinol for hyperuricemia which was started 1 year back. There was history of similar lesions 6 months back which healed within 1 month of stopping allopurinol and he started taking the drug for the past 4 months on his own without any medical advice. Histopathological examination showed superficial and deep perivascular lymphocytic infiltrate with numerous histiocytes scattered in the intersititum of reticular dermis and abundant mucin in between the histiocytes. Allopurinol was implicated as an etiological agent and dramatic improvement was seen after stopping the drug for a period of 4 weeks. Naranjo's algorithm showed a probable association with a score of 6. Thus the final diagnosis of allopurinol induced generalised interstitial granuolma annulare was made. Patient was advised to continue antileprotic drugs, low purine diet and avoid allopurinol intake.