Delayed tooth eruption in congenital hypertrichosis lanuginosa.

Hypertrichosis in childhood is found in a variety of conditions and may be localized or generalized.' Localized hypertrichosis may be related to trauma, nevi, or spina bifida occulta. Generalized hypertrichosis can occur with a variety of metabolic, chromosomal, and congenital disorders; these include Gorlin syndrome, Cornelia de Lange syndrome, Leprechaunism, the porphyrias and mucopolysaccharidoses, trisomy 18, gingival hyperplasia with hypertrichosis, and the congenital hypertrichoses. Preor postnatal drug exposure with drugs such as glucocorticoids, cyclosporin, and maternal alcohol abuse in pregnancy may also result in hypertrichosis. In the congenital hypertrichoses, excessive hair growth is the primary disorder. The terminology of these disorders has been confused in the past but they have been described as congenital hypertrichosis universalis, transient congenital hypertrichosis universalis, and congenital hypertrichosis lanuginosa. The present case is one of congenital hypertrichosis lanuginosa in which the body is covered with dense lanugo (fetal) hair at birth, which persists and is constantly renewed throughout life. Congenital hypertrichosis lanuginosa is very rare; a review of the literature in 1969 found reports of only 32 cases. The inheritance is believed to be autosomal dominant with varying expressivity" and there are several families in which the disorder has been described in more than one generation,'' with a four-generation pedigree in one Burmese family. Others have reported excessive hairiness in previous generations, suggesting the idea of varying expressivity. The disorder is primarily an aesthetic one; the lanugo hair is constantly renewed throughout life, but in some cases does appear to diminish with age. The growth of the hair is dense along the back, particularly at the base of the spine, and can block the external nose and external auditory canals, causing apparent deafness. The only parts of the body free from hair are the palms of the hands and soles of the feet. In the past, individuals with extremes of hypertrichosis of all types have been widely exhibited in side-shows and described in terms such as "dog-faced boy", "the nondescript", and "human werewolf'.'' Dental anomalies such as neonatal teeth, hypodontia, the presence of supernumerary teeth, and "defects" in the enamel have been reported in association with hypertrichosis lanuginosa.'' The present case illustrates delayed eruption of primary and permanent teeth resulting in unusual root morphology of primary molar teeth, and also enamel hypoplasia.