Otitis externa may also be present. Lesions are painful, but not pruritic. Differentials include staphylococcal dermatitis, demodicidosis, and drug eruption. Cytology and histopathology do not reveal organisms, only pyogranulomatous inflammation . Early, aggressive therapy is indicated to try and prevent scarring, which can be severe.
Relapses are uncommon.
The etiology of this disease is unknown, and the name is simply descriptive of the lesions. Panniculitis refers to inflammation of subcutaneous fat, and the disease is characterized by deep-seated cutaneous nodules that may become cystic, ulcerated, or develop draining tracts. May be single or multiple, may be generalized or localized, and may vary in size from a few millimeters to several centimeters. The nodules may be firm or soft. When draining, they discharge oily, yellow to brown to bloody material.