We fully agree with the comments of Dr Morton referring to the relevance of fecal porphyrins in the diagnosis of PCT. The presence of heptacarboxylporphryin and isocoproporphyrin in feces even with normal amounts of total porphyrins confirms the diagnosis of PCT.1 Therefore, urine and fecal samples of the population of the study were both collected. Fecal porphyrins were determined later on, and the results will be published. A qualitative test was performed on all samples. No fluorescence was detected indicating increased porphyrin concentration.
Herrero C, Ozalla D, Lecha M, Mascaró JM, To-Figueras J, Sunyer J, Sala M. Fecal Porphyrin Measurements Are Crucial for Adequate Screening for Porphyrinopathy—Reply. Arch Dermatol. 2000;136(4):554. doi: