<prompt> A 40 year old farmer with a history of recurrent attacks of porphyria complains of itching when exposes to the sun and maculopapular rash on sun exposed areas, his symptoms are exaggerated in the summer. The diagnosis is :Seborrheic dermatitisContact dermatitisPsoriasisPorphyria cutanea tarda  <response>: Ans. is d Porphyria Cutanea Tarda Sun induced maculopapular lesions, ho recurrent attacks of porphyria are classical features of porphyria cutanea tarda.Porphyria Cutanea TardaCommonest PorphyriaSun induced subepidermal blisters on face and hands.Mostly seen in alcoholics with liver damageEstrogens steroids also aggravate itTt - Venesection or chloroquineOther Facts about porphyriaIn acute intermittent porphyria skin lesions are absentOther cutaneous porphyrias are :Erythropoietic porphyriaVariegate porphyriaSeborrheic Dermatitis present as greasy scales and has no relation with sunlightPsoriasis presents as erythematous plaques topped by silvery scales, Exposure to sunlight can aggravate psoriasis although in majority it has beneficial effect.Contact dermatitis- The lesions are usually erythematous vesicles and bullae and there will hO exposure to allergens. 