[Blasch-kolinear psoriasis revealed by infliximab therapy].

BACKGROUND: Blaschko-linear psoriasis is a rare disease about which only a few publications have appeared in the literature. This form of psoriasis poses problems of differential diagnosis with regard to other forms of inflammatory Blaschko-linear dermatoses. Herein, we report an original case, the linear nature of which was revealed by treatment with infliximab. CASE REPORT: A 29-year-old man presented chronic psoriasis present for 17 years and resistant to various forms of systemic therapy. Treatment with infliximab 5mg/kg given on D1, D15 and two-monthly, thereafter resulted in practically complete resolution of all skin lesions after the fourth infusion. The only remaining lesions were psoriatic erythematous-squamous, non-pustular lesions with a Blaschko-linear pattern, limited to one side, on the left arm and left leg. These lesions persisted after 10 courses of infliximab, although no other lesions reappeared. DISCUSSION: This case was original in terms of the revelation of Blaschko-linear lesions during treatment with infliximab, despite the complete disappearance of diffuse psoriatic plaques, thus suggesting the existence in this patient of two cell populations, each having a different response to biotherapy.