chagoma

Chagoma is a localized cutaneous lesion associated with acute infection by Trypanosoma cruzi, the parasite that causes Chagas disease. It represents the inoculation site reaction after entry of the parasite through the skin, typically via the feces of a triatomine bug or through contaminated handling. The lesion usually appears days to weeks after exposure.

Clinically, a chagoma presents as a firm, erythematous, indurated nodule or swelling at the site of inoculation. It may be tender and accompanied by regional lymphadenopathy. A related but distinct presentation is Romaña’s sign, which is periorbital swelling from conjunctival inoculation and is not itself a chagoma.

Diagnosis is based on clinical suspicion in an endemic or exposure setting. In the acute phase, parasites can be detected in blood smears or by molecular methods such as PCR. Serology becomes more informative later in infection. Biopsy of the lesion can reveal intracellular amastigotes within tissue cells.

Treatment involves antiparasitic therapy, typically with benznidazole or nifurtimox, and is most effective when started early. Chagomas may resolve with treatment, but infection can progress to chronic Chagas disease, which may cause cardiomyopathy or megasyndromes over time.

Epidemiologically, Chagas disease is most common in Latin America but has spread globally through migration. Prevention focuses on vector control, reducing exposure to triatomine bugs, and avoiding contact with contaminated insect feces.