Plasma cell panniculitis is a rare histopathological variant of morphea profunda. Its occurrence in two siblings has been reported once. We report a new case in which a brother and a sister with a family history of consanguinity presented plasma cell panniculitis of long duration.A man and his sister, 38 and 28 years old respectively, presented thick hyperpigmented indurations of the trunk and thighs since puberty. Previous investigations did not lead to any definitive diagnosis. Deep cutaneous specimens taken from both patients exhibited indistinct histological features of plasma cell panniculitis.Morphea profunda is a deep-localized variant of scleroderma. The presence of predominant plasma cell infiltrate suggests a rare type of morphea profunda named plasma cell panniculitis. Subcutaneous plasma cell infiltrate has been described in many diseases such as lupus profundus and lymphoplasmocytic panniculitis of Lyme disease. The family history of consanguinity, similar age of onset and identical clinicopathological presentation suggest a genetic role in this disorder. This is the second report of plasma cell panniculitis in two siblings with a history of consanguinity.