[Immunogenetics of psoriasis: update]

Psoriasis is a chronic inflammatory skin disease often benign, affecting 2-3% of the total world population. Psoriasis is a multifactorial disease. To present recent advances in the immunologic mechanisms and susceptibility genes involved in the pathogenesis of psoriasis. We presented a literature review of recent genetic and immunological basis of psoriasis to better understand the pathomecanisms of this disease and discuss the contribution of the Tunisian work in this area. Recent works focalized mainly in immunology and genetics. Current progresses in molecular biology have allowed to better characterize the immunogenetic abnormalities in psoriasis. Psoriasis is a multifactorial disease model in which environmental factors [psychological, climate, traumatic, infectious, and viral] seem to be triggering factors when associated with a particular immunogenetics predisposition

[Pulmonary tuberculosis associated with cutaneous and mediastinal sarcoidosis - a case report]

The association of sarcoidosis and tuberculosis is rare and its differentiation is sometimes very difficult. We report a case of a 49 years woman presenting insidious erythematous and nodular lesions of the face that histologically revealed non caseating granulomas of the dermis and diagnosed as cutaneous sarcoidosis. We have concomitantly diagnosed evolutive pulmonary and nasal tuberculosis treated during 2 months with isoniazid, rifampicin, pyrazinamid and streptomycin and for 6 months with isoniazid and rifampicin. The evolution of nasal obstruction was favorable and pulmonary bacteriologic examination was negative at two months treatment but mediastinal adenopathy and cutaneous lesions were unchanged. The patient was treated with Isotretinoin 60 mg daily during 6 months inducing regression of cutaneous lesions but adenopathy still unchanged. At 8-months follow-up the patient is still free of cutaneous recurrence. In our patient cutaneous sarcoidosis appeared concomitantly with evolutive tuberculosis raising further questions about the role of mycobacterium in causing this granulomatous disorder. In addition cutaneous nodules responded to isotretinoin suggesting that this drug can be useful in cutaneous sarcoidosis