Scalp of a patient with folliculitis decalvans. Folliculitis decalvans is a rare chronic inflammation of the scalp that results in scarring hair loss. It is caused by an infection of hair root cells, usually by Staphylococcus bacteria. The affected area of the scalp becomes red and swollen and may form scaly patches, scabs and crusts. A characteristic feature of the disorder is that several hairs (?˜tufts?? exit from the same hair follicle on the scalp skin, leading to patches of baldness. Treatment is aimed at reducing inflammation and preventing further scarring.