A 40 year old farmer with history of recurrenmt attack of porphyria complains of itching when exposed to the sun and maculopapular rashes on sun exposed area. His symptoms are exaggerated in summer. The diagnosis is :
D i.e. Porphyria cutanea tarda Two types of porphyria are photosensitive Porphyria cutanea tarda Is most common type of porphyria and is caused by decreased activity of enzyme uroporphyrinogen decorboxylase. - Two types of PCT are: (1) Sporadic or acquired type, seen in individuals ingesting ethanol or estrogens; (2) inherited type. Both forms are associated with increased hepatic iron stores. Predominant clinical feature is a chronic photosensitivity characterized by increased fragality of sun exposed skin, paicularly areas subject to repeated trauma such as dorsum of hands, forearms, face and ears. The predominant skin lesions are vesicles and bullae, that rupture, producing moist erosion, often with a hemorrhagic base, that heal slowly with crusting and purplish discolouration of the affected skin. Hyperichosis, mottled pigmentary change, and scleroderma like induration are associated features. - Confirmation of diagnosis is done by measurement of urinary porphyrin excretion, plasma porphyrin assay and by assay of erythrocyte and/or hepatic uroporphyrinogen decorboxylase. Erythropoietic porphyria - Erythropoietic porphyria originate in the bone marrow and is d/t decrease in mitochondrial enzyme ferrochelatase; congenital type is d/t deficiency of URO synthetase. - Clinical features include an acute photosensitivity, characterized by subjective burning and stinging of exposed skin that often develops during or just after sun exposure. These may be skin swelling, and after repeated episodes, wax like scarring. - Diagnosis is confirmed by demonstration of elevated levels of free erythrocytes protoporphyrins Detection of increased plasma protoporphyrin helps to differentiate lead poisoning & iron deficiency anemia; in both of which elevated erythrocyte protoporphyrin levels occur in the absence of cutaneous photosensitivity & of elevated plasma protoporphyrin levels. * Seborrhic Dermatitis: presents with greasy scales & severe dandruff. Cradle cap is seborrhic dermatitis of scalp, face & groin in infant. But infant cradle cap is found in ptyriasis capititis complicated by seborrheic dermatitis.
Seborrheic dermatitis
Contact dermatitis
Psoriasis
Porphyrea Cutanea tarda