Pinta (disease)

Pinta progresses through three distinct stages. The primary stage appears 2–4 weeks after infection as a small, erythematous papule that enlarges into a scaly plaque, often on exposed areas like the hands, feet, or face. The secondary stage, developing months to years later, features multiple disseminated, hyperpigmented or erythematous patches that gradually become depigmented, giving a mottled appearance. The late stage, after several years, results in atrophic, depigmented macules with hyperkeratotic borders, often on the extremities. Unlike syphilis, pinta does not affect internal organs, bones, or the nervous system.¹

Pinta is endemic in remote, impoverished communities of Mexico, Central America, and South America, particularly in the Amazon basin and Andean regions. It predominantly affects children and adolescents, with transmission occurring through direct skin-to-skin contact with infectious lesions, often facilitated by crowded living conditions and poor hygiene. The disease is not sexually transmitted, and no animal reservoir is known. Due to improved living standards and mass treatment campaigns, the prevalence has declined dramatically, but sporadic cases still occur in isolated populations.²

Diagnosis is primarily clinical, supported by serological tests for treponemal antibodies (e.g., TPHA, FTA-ABS), which are positive in all stages. Dark-field microscopy of lesion exudate can demonstrate spirochetes in early lesions. Pinta must be differentiated from other causes of depigmentation, such as vitiligo, leprosy, and pityriasis versicolor. Treatment is simple and highly effective: a single intramuscular dose of benzathine penicillin G (1.2 million units for adults, 600,000 units for children) cures the infection, halts progression, and prevents transmission. For penicillin-allergic patients, doxycycline or tetracycline are alternatives.

Pinta is the mildest of the endemic treponematoses, yet it shares a close genetic relationship with yaws and syphilis, with the causative subspecies differing by only a few genes. The disease was historically known as 'carate' in Spanish-speaking regions, and its name 'pinta' derives from the Spanish word for 'painted,' referring to the mottled skin appearance. In the 1950s, the World Health Organization launched a global campaign to eradicate endemic treponematoses, including pinta, using long-acting penicillin, which dramatically reduced cases. However, pinta has never been formally eradicated, and recent molecular studies have identified distinct genetic lineages in Colombia and Brazil, suggesting ongoing transmission in remote areas.

Treponema pallidum pertenue

A subspecies of the spirochete bacterium that causes pinta.

Endemic treponematoses

A group of chronic bacterial infections caused by Treponema pallidum subspecies, including yaws, bejel, and pinta.

Depigmentation

Loss of skin color due to destruction of melanocytes.

Benzathine penicillin G

A long-acting form of penicillin used as the standard treatment for pinta.