Focal Dermal Hypoplasia

Abstract

Focal dermal hypoplasia (FDH) consists of various skin anomalies and abnormalities of the skeleton, especially the limbs. The skin features include focal absence of skin and linear or reticular hyperpigmentation or hypopigmentation of the skin, herniation of fat through the dermal defects, and multiple papillomas of the mucous membranes or skin, such as in the axilla and around the anus and vulva. Oral anomalies, in addition to lip papillomas, include hypoplastic teeth. Spotty hypotrichosis of the scalp or pubic hair has been described. Digital anomalies comprise syndactyly, postaxial polydactyly, brachydactyly, camptodactyly, and absence deformities such as oligodactyly. The combination of split-hand/foot with syndactyly is common. Limb anomalies are often asymmetric. Short stature occurs. Right-sided clavicular pseudoarthrosis is frequently found. Ocular anomalies, including strabismus, microphthalmia, and coloboma of the iris, choroid, and retina, may be present in some cases. Delayed psychomotor development occurs in many patients. Striated bones are a frequent feature. Hypodontia is a frequent teeth anomaly, but supernumerary teeth, enamel dysplasia, and malocclusion are also seen.