What is the X in X-mas?
pemphigus pem·phi·gus (pěm'fĭ-gəs, pěm-fī'gəs)
Any of several acute or chronic skin diseases characterized by groups of itching blisters.
a group of skin diseases characterized by large blisters that appear on the skin and mucous membranes. Pemphigus diseases include pemphigus vulgaris, pemphigus vegetans, pemphigus foliaceus, pemphigus erythematosus, and benign familial pemphigus.