Hidrotic Ectodermal Dysplasia: Evaluation through Magnetic Resonance Imaging (MRI)

To the Editor: Hidrotic ectodermal dysplasia is an uncommon autosomally dominant disorder of keratinization, characterized by hypotrichosis, nail dystrophy, and palmo-plantar hyperkeratosis (1–3). The triad is its usual expression; other associated features such as dental hypoplasia may also be encountered (4). This case in addition demonstrates the possible role of MRI of the cranium in order to evaluate morphological variations, if any, which may be predictive of the possible course of the disease. Standard texts (5) lack investigative overtures to form or delineate the probable sequence in the evolution of the disease. Magnetic resonance imaging (MRI) (6) is currently being utilized more and more to define soft-tissue and bone tumors. Its sophistication in defining the anatomy of organ(s) or their abnormalities is unquestionable. For these reasons, this procedure was used on the current patient. A 4-year-old boy is one of three children of an apparently healthy, middle-aged couple coming from a well-to-do socioeconomic background. The child was the product of normal full term delivery. His weight at the time of birth was 4.5 kilograms; his 12-yearold brother was premature at 7 months and his sister, aged 7 years, was also born full term. His mother had two abortions and a miscarriage at 5 months of gestation before the birth of this child, and she had hormonal treatment during her pregnancy. Ever since the birth of the child, the parents have noticed moderate to severe itching followed by formation of wheals and profuse sweating, especially over the scalp and rest of the body, irrespective of seasonal variations. He also had spotty pigmentation confined to pressure areas. He has a peculiar physical appearance; the head is much longer than it is broad (cephalic index <75.9 cm). The scalp has sparse hair, thin eyebrows, prominent eyes, maxillary depression, and prominent thick lips (Fig. 1). Teeth are apparently normal. Spoon nail (koilonychia) and paronychia were conspicuous in a few of his finger and toenails. The intelligence quotient (I.Q.) was between 70 and 90. The child’s parents were apparently disturbed by his slow physical and mental growth. They seemed dissatisfied and frustrated at the repeated indifferent response of the treating physicians. This time they were determined to explore the possible natural history of the disease. Accordingly, after thorough deliberation, it was decided to undertake magnetic resonance imaging purely for its academic undertones. In the meantime, a referral to a neurologist was made. He too advised follow-up MRI in order to define any morphological variation. Periodic follow-up was advised. Recently, the patient was examined again to detect any further progression of the disease. The parents this time seemed more confident, because the child has been promoted to a The Journal of Dermatology Vol. 29: 606–608, 2002