Las poroqueratosis son un grupo heterogéneo de trastornos de la queratinización epidérmica, de presentación infrecuente. Se caracterizan clínicamente por pápulas hiperqueratósicas que confluyen formando placas anulares con un centro atrófico y bordes sobreelevados. Hay seis variantes clínicas. El examen histopatológico evidencia la característica laminilla cornoide. Se presenta el caso de una niña de 2 años con diagnóstico de poroqueratosis de Mibelli y respuesta parcial al tratamiento tópico con tretinoínaal 0,025%, que actualmente continúa en seguimiento clínico.

References1 Yannicelli S, Ryan A. Improvements in behaviour and physical manifestations in previously untreated adults with phenylketonuria using a phenylalaninerestricted diet: a national survey. J Inherit Metab Dis 1995; 18: 131-134. 2 Lin SY, Nui DM, Tu CP, Cheng YD, Lin HL. Evidence of L-cysteinesulfinic acid in PKY neonatal hair roots, with disappearance after dietary control. Ultrastruct Pathol 2000; 24: 351-352. 3 Itin PH, Fistarol SK. Hair shaft abnormalities -clues to diagnosis and treatment. Dermatology 2005; 211: 63-71. 4 VanSande M. Hair amino acids: normal values and results in metabolic errors. Arch Dis Child 1970; 45: 678-681. 5 Wiest LG, Lutz P, Jung EG, Paweletz N. Morphological and biochemical investigations of hairs in inborn errors of amino acid metabolism. Arch Dermatol Res 1976; 256: 53-65. 6 Olsen EA. Diffuse alopecia: telogen hair loss. Figure 2Hyperpigmented macular lesion over the hard palate, under the denture.

A case is described in which a clinical diagnosis of "metaphysial dysostosis" was made, but in which histological examination of involved bones showed the changes of rickets, presumably renal, with secondary hyperparathyroidism.