Porphyria cutanea tarda in children: epidemiological study of a rare disease in Argentina

Porphyria cutanea tarda (PCT), the most common porphyria, is caused by a decreased activity of uroporphyrinogen decarboxylase (UROD). PCT is generally sporadic, but in about 25% of cases, the disease is transmitted as an autosomal dominant trait (familial PCT). Few cases of PCT with onset in childhood have been reported to date. The aim was to perform a retrospective analysis of these rare cases, including all patients diagnosed with PCT from 1977 to present, with disease onset occurring before the age of 18.

We analyzed 28 patients, 15 males and 13 females, ranging from 3 to 16 years old.

Characteristic biochemical alterations, such as elevated urinary levels of porphyrins with typical excretion pattern, high plasma porphyrin index, reduced erythrocyte UROD activity, and typical cutaneous lesions of PCT were observed in all patients. Molecular analysis revealed the genetic heterogeneity inherent to PCT, with certain variants being prominent within the Argentinian cohort. Potential precipitating factors of the disease were also described.

This study provides a comprehensive analysis of childhood-onset PCT in the Argentinian population, shedding light on both genetic and environmental factors contributing to the disease. We emphasize the crucial need for early diagnosis, particularly in pediatric cases, and remark on the importance of genetic studies among family members to prevent the delayed recognition of PCT in high-risk individuals. Additionally, the study discusses the role of environmental factors in disease onset and the importance of carefully monitoring drug use in PCT patients.