The incubation period is about 3 weeks, but primary lesions are encountered infrequently. Usually, the first manifestations are of the secondary type and consist of indurated mucous membrane lesions of the lips, tongue, and oropharynx or consist of papillomas at the oral commissures. At times, both mucous membrane lesions and papillomas may be present. Disseminated papillomas are most common in moist areas such as the axillae, the nasolabial folds, and the anal cleft. As in yaws, painful periostitis of long bones occurs.
Secondary lesions heal slowly over many months, after which a prolonged latent period occurs.
Late manifestations include gummatous lesions of the skin and bones with erosive palatal perforation and destruction of the nose and adjacent tissues. Cardiovascular or neurologic complications and congenital infections rarely, if ever, occur. Diagnosis and treatment are the same as those for yaws. The mode of transmission is not certain but is believed to be direct contact. Clinical Features, Diagnosis, and Treatment Pinta is a disease solely of the skin.