Pyoderma chronica papillaris et exulcerans: causes, symptoms, diagnosis, and treatment

Pyoderma chronica papillaris et exulcerans is a chronic infectious skin disease characterized by papillary or verrucous hyperplasia, sinus tracts, and ulcers.


Pyoderma chronica papillaris et exulcerans is caused mostly by staphylococcus aureus, but streptococcus, Escherichia coli, diplococcus, and Proteus can also be cultured in the lesion. The disease is often secondary to minor trauma, insect bites, scratches, various pyoderma or eczema. Malnutrition and decreased body resistance are closely related to the onset of the disease.

Signs and Symptoms

Red pustules or small nodules occur around the lesions of trauma, eczema or pyoderma, merging with each other, gradually evolving to purplish red edematous infiltrative plaques, ulcers, and papillary or verrucous hyperplasia. Ulcers are undermined, with filthy crusts. Skin lesions often heal on one side and expand creepingly on the other side. Sometimes perforated sinus tracts are formed. Pus can be discharged from the perforated sinus tracts when pressed. Local lymph nodes are enlarged. Skin lesions are usually solitary, mainly in the limbs, especially in the back of hand, as well as trunk and face, more common in old males, especially farmers, with subjective mild pain. Pyoderma chronica papillaris et exulcerans develop slowly, and repeated recurrences are often present.


Hyperkeratosis, parakeratosis, and acanthosis are visible in the epidermis. Initial dermal edema, vasodilation, and lymphangiectasis, followed by diffuse or focal neutrophil, lymphocyte, and histiocytic infiltration and localized abscess, can be seen. Exudative inflammation and necrosis are present in ulcers.


On the basis of clinical presentations, such as ulcer, perforated sinus tracts, papillary or verrucous hyperplasia, diagnosis is not difficult.

Differential diagnosis

Tuberculosis verrucosa cutis is generally without pustules but with obvious verrucous hyperplasia.

Pyoderma vegetans is generally without ulcers, mainly in the folded skin such as armpits and groin.

Chromoblastomycosis can be differentiated by fungal microscopy and culture.


Systemic and topical antibiotics can be administered. Rifampicin, autogenous vaccine, and multivalent vaccines are effective. In addition, laser, ultraviolet light, and other adjuvant treatment can be used.