Tropicaloid ulcer: causes, symptoms, diagnosis, and treatment

Tropicaloid ulcer is an infectious disease caused by Corynebacterium mycetoides.


Corynebacterium mycetoides is an aerobic, Gram-positive bacillus, widely distributed in nature in the microbiota of animals. The bacterium is mainly transmitted through contact, and the disease is epidemic in the desert regions.

Signs and Symptoms

The clinical manifestations are similar to those of desert sores, predominantly in the extremities. The ulcer can be up to 2cm in diameter, and the base is covered with diphtheroid pseudomembrane. Obvious subjective symptoms are usually absent. The disease can heal spontaneously, leaving pigmentation and scars after healing.


Diagnosis depends upon the clinical manifestations and epidemiology.


Penicillin is effective, and topical antibiotic ointment is feasible.