* Vietnam.
** Inner Vision Women's Ultrasound, Nashville, Tennessee, USA; Department of Obstetrics and Gynecology, University Hospital Brno, Czech Republic.
Introduction
Harlequin ichthyosis/ Ichthyosis congenita is the most severe and often lethal form of congenital ichthyosis. There is extreme thickening of the keratin layer of the skin. The affected fetus is covered in the thick plates of cornified skin separated by deep cracks or fissures. The tight skin causes facial deformities, microcephaly and also contractures of the extremities. The affected neonates are at risk of respiratory distress due to restricted breathing, sepsis, dehydration, temperature instability, feeding problems which can often lead to the fatal consequences.
Incidence for all types of autosomal recessive congenital ichthyosis is 0.05:10,000. The Harlequin ichthyosis is very rare.
Ultrasound findings
- Head: cracked skin; open eyes, due to severe eversion of the eyelids (ectropion); wide lips, fixed into the wide grimase (eclabium)
- Skin: thickened with multiple fissures
- Extremities: deformation, hypoplasia of the fingers and toes
3D ultrasound helps to make the diagnosis.
Inheritance
Harlequin ichthyosis is an autosomal recessive condition. Heterozygotes (carriers) are asymptomatic. Genetic counseling shoud be offered to the parents who are affected or have an affected child. Disease-causing alleles must be identified before prenatal testing is performed.
Differential diagnosis
- Sjögren-Larsson syndrome
- Netherton syndrome
- Gaucher disease
- Keratitis-ichthyosis-deafness syndrome
- Trichothiodystrophy ("sulfur-deficient hair")
- Chanarin-Dorfman syndrome
- Conradi-Hünermann syndrome (X-linked dominant chondrodysplasia punctata)
- Hypohidrotic ectodermal dysplasia
- Bullous autosomal dominant ichthyoses
Prognosis Prognosis for such an affected individuals used to be very unfavorable. The quality of life improved with introduction of isotretinoin. Long term survival is still very low. The oldest surviver lives in United Kingdom and is 26 years old at the moment.
Case report The following images present a case of ichthyosis. A 39-year-old G4P3 with non-contributive personal or family history was referred to our hospital at 29 weeks of gestation due to an anomaly of the face. We performed an ultrasound scan and confirmed the facial anomaly together with multiple other findings:
- Face with thick lips; cracked skin
- Skin, thick and cracked
- Extremities with hypoplastic fingers and toes
Our diagnosis based on the ultrasound findings was ichthyosis. The pregnancy was terminated at 30 weeks of gestations.
Images 1,2: Image 1 shows a thickened, Harlequin lips. Image 2 shows a cracked skin on the fetal face.