Hypopigmented macules in neurofibromatosis type 1: A case control study

To the Editor: Neurofibromatosis type 1 (NF1) is an autosomal dominant, neurocutaneous disorder. In most cases, cutaneous pigmentary manifestations are main diagnostic clue. NF1 characterized by hyperpigmentation—café au lait macules (CALMs), skinfold freckling, and melanotic plexiform neurofibromas. However, hypopigmented lesions have received little attention in patients with NF1. Riccardi1Riccardi V.M. Albright's syndrome.Dermatol Clin. 1987; 5: 193-203Abstract Full Text PDF PubMed Google Scholar described presence of (HMs) approximately 2% to 3% 1987. Studies regarding physiopathology HM lacking. This study aimed characterize prevalence HMs our pediatric diagnosed A case-control prospective design was used compare 108 (younger than 18 years) 137 healthy age-matched control individuals. All included cases cohort had a confirmed diagnosis We required third National Institutes Health criterion or genetic testing children who exclusively showed CALMs freckling. The were enrolled from October 2014 January 2017. also assessed number, location, size, morphology patients. Well-circumscribed lesions, those early onset life, stable hypomelanosis considered HMs. Patients postinflammatory other possible causes hypopigmentation as well vitiligo nevus anemicus (NA) excluded. became erythematous after rubbing, unlike NA. participants signed informed consent. observed that 13.9% (n = 15) group 4.4% 6) presented significantly higher (Pearson chi-square test P value .008). Demographic clinical characteristics shown Table I. sizes ranged 0.5 9 cm, all well-defined sharp margins (Fig Supplemental Fig 1; available via Mendeley at https://doi.org/10.17632/6w3g76nyxr.2). Parents recalled birth 4 (22.2%) children.Table IDemographic characteristicsClinical featuresPatients (N 108)Control individuals 137)HMs, n (%)15 (13.9)6 (4.4)Age when first noticed, y Mean4.24.7 Range0-103-13Sex, (%)P .132P Male9 (60)3 (50) Female6 (40)3 (50)Distribution Solitary, (%)12 (80)6 (100) Range1-2 Mean ± SD1.2 0.41Location, (%) Thorax6 Legs5 (33.3)1 (16.6) Abdominal3 (20)0 Arms2 (13.3)1 Lumbar1 (6.6)1 Neck1 (6.6)0Size, <14 (22.2)2 (33.3) 1-513 (72.2)4 (66.6) >51 (5.6)0Morphology, Ash-leaf6 (33.3)0 Rounded5 (27.8)3 Oval5 Polygonal2 (11.1)0HM, Hypopigmented macule; SD, standard deviation. Open table new tab HM, Although present almost NF1, circumscribed has not been characterized. differential for tuberous sclerosis complex (TSC) hypomelanotic macules, NA, vitiligo, pityriasis alba, hypopigmentation, piebaldism. simultaneous occurrence TSC single individual extremely rare,2Samanta D. Bosanko K.B. Zarate Y.A. An infant ash-leaf café spots: case double phakomatosis.Acta Neurol Belg. 2016; 117: 323-324Crossref Scopus (1) did show signs TSC. fulfilled Coupe criteria could be depigmentosus (ND).3Coupe R.L. Unilateral systematized achromic naevus.Dermatology. 1967; 134: 19-35Crossref (40) Scholar,4Kim S.K. Kang H.Y. Lee E.S. Kim Y.C. Clinical histopathologic depigmentosus.J Am Acad Dermatol. 2006; 55: 423-428Abstract (46) ND best congenital, throughout well-circumscribed lesion.3Coupe occurs 0.4% 0.7% infants,5Baselga E. Disorders hypopigmentation.in: Schachner L.A. Hansen R.C. Pediatric Dermatology. 4th ed. Mosby Elsevier, Philadelphia, PA2012: 719-722Google so series (13.9%) expected. Thus, results suggest statistical relationship between (P < pathophysiologic explanation population remains unknown. conclude common finding either coincidence truly associated Basic research investigations needed achieve better knowledge physiopathology.