Persistent nasal crusting due to hypohidrotic ectodermal dysplasia.
Hypohidrotic ectodermal dysplasia is an hereditary condition of the ectodermal tissues which may escape recognition because of lack of clinical awareness due to its rarity. Otorhinolaryngological features of this syndrome include chronic respiratory tract infections, persistent foul-smelling nasal discharge and crust formation, and hearing problems. The condition is usually an X-linked recessive disease affecting mainly ectodermal tissue, although nonectodermal tissue may also be affected. The notation 'ectodermal' is used because ectodermal tissues are always involved. The syndrome is characterized by complete or partial absence of sweat glands, sparse hair growth, absent or deformed peg teeth, sparse sebaceous glands, occasional absence of salivary and lacrimal glands, scanty mucous glands and deficient cilia. We describe two children with this disorder with specific reference to the effect on the upper respiratory tract.