Anders Vahlquist, Agneta Gånemo, Maritta Pigg, Marie Virtanen, Per Westermark
DOI: 10.1080/00015555-0370

Congenital ichthyosis comprises a rare group of usually
monogenetic diseases that present at birth as a collodion
phenotype or as variable degrees of ichthyosiform
erythroderma, with or without superficial blisters. Depending
on which gene mutation causes the disease, the
skin problems later in life may range from a severe
lamellar or bullous ichthyosis to mild or only focally
expressed hyperkeratotic lesions. It is obviously important,
but sometimes painstakingly difficult, to make a
correct diagnosis already in infancy. Fortunately, recent
advances in our understanding of the molecular
genetics of ichthyosis have led to several new diagnostic
tools that are continuously being updated. Based on
this development, and on our own 5 years of experience
in a national genodermatosis centre, we describe
127 cases of congenital ichthyosis examined in childhood
or adulthood. Applying a combination of phenotypic
and genotypic criteria, the patients were classified
into three main groups: 1) Bullous ichthyosis
(epidermolytic hyperkeratosis) and related disorders
due to keratin mutations (n=21); 2) Non-bullous ichthyosiform
erythroderma and lamellar ichthyosis
mainly due to transglutaminase 1 mutations (n=80); 3)
Syndromic ichthyosis, i.e. systemic (multi-organ) diseases
due to many different causes (n=26). Each group
could be further stratified into 4–11 entities using mutation
analysis, electron microscopy of epidermis and
various other techniques. Our findings are discussed
in relation to recent data in the literature emphasizing
the clinical usefulness of various diagnostic procedures
for ichthyosis.