ABSTRACT
Incidence is estimated at 1:100 000. In Italy, patients with ‘pure’ anhidrotic ectodermal dysplasia number about 100 out of 57 million inhabitants.
Clinical findings ● Abnormalities of the epidermis and adnexa are extremely variable
Figure 15.1 ● Babies may be born with a ‘post-mature’ ichthyotic presentation, rarely as a classic
‘collodion-baby’ presentation with medium-sized lamellae and slight underlying erythema (Figure 15.1)
Figure 15.2 ● Peculiar facies characterized by frontal bosses, mild hypertelorism with antimongolian
slants, malar region hypoplasia with small saddle-shaped nose and hypoplastic alae, O-shaped mouth with prominent lips and possibly a pointed chin. External ears may be low-placed and hypotrophic (Figures 15.2 and 15.3)
● Epidermis is dry fine and smooth with xerotic patches and eczematous areas (Figure 15.2)
● Body hair follicles are diminished or absent ● Hair is usually blond, fine and scanty, even if partial or total alopecia or hypotrichosis
may be present (Figure 15.4) ● Eyebrows and eyelashes may be rudimentary or absent (Figures 15.2-15.4) ● Nails are usually less involved in hypohidrotic ectodermal dysplasia (HED), but some
degree of dystrophy can be noted as split, fragmented, striated and discolored laminae. Less frequently, nails are thickened (Figure 15.5)
● Eccrine sweat glands are dramatically dimished, hypoplastic or even absent, with extreme heat intolerance ● Absent or rudimentary oral mucous glands and salivary glands lead to xerostomia
Figure 15.3 ● Apocrine glands are hypoplastic ● Female carriers may present minimal or discrete signs of the disease such as partial
alopecia, abnormal dentition (Figure 15.6), hypodontia, some degree of the ‘facies’ and streaks of epidermis without appendages along Blaschko’s lines (Figures 15.7 and 15.8) that are more visible with the ‘starch-iodine’ test to evaluate sweat gland function (Figure
15.9)
Extracutaneous symptoms
● Hypo-or anodontia is the hallmark of the disease, with abnormal and defective dentition
● Conical or rudimentary teeth are present and caries is very common (Figure 15.10) ● Lacrimal glands are rudimentary or hypoplastic ● The dense texture of nasal secretions promotes mucous stasis with uncomfortable crust
formation in the choanae and subsequent infection of the paranasal sinuses ● Hypoplasia of ear mucus glands leads to cerumen impaction and chronic otitis media
● Mucus glands are diminished or hypoplastic in the entire respiratory tract, leading to susceptibilty to
Figure 15.4
Figure 15.5 recurrent infections of both upper and lower sections
● Dysphagia and stypsis are common symptoms in these patients and are due to extreme hypofunction of mucous glands in the whole gastrointestinal system
● Mammary glands may be absent ● Abnormalities in immune function, both humoral and cellular, have been reported
● Mental retardation is reported in some cases
Figure 15.6
Figure 15.7
Course and complications
● Unexplained recurrent fever and extreme heat intolerance during hot weather may lead to seizures and coma, especially during the first year of life
● Recurrent infections of the upper respiratory tract and otitis media may become chronic ● Hypoanodontia is linked to diminished intake of food, anemia and failure to thrive
Figure 15.8 ● Atopic dermatitis is frequently associated ● Stypsis
Female carrier cases of hypohydrotic ectodermal dysplasia is often misdiagnosed in neonatal age and in early infancy. The disease is steady during life in males. Uneventful amelioration is reported in some cases, especially in female carriers.
