Ichthyoses constitute a large group of cornification disorders that affect the entire integument. The skin is characterized by visible scaling and in many cases by
inflammation, for example, in bullous/keratinopathic
ichthyosis or
Netherton syndrome. From the viewpoint of classification it is useful to distinguish non-syndromic from syndromic types of
ichthyosis.
Ichthyosis vulgaris and recessive
X-linked ichthyosis are common disorders - often of delayed onset, in contrast to congenital
ichthyoses, which belong to the group of
rare diseases and present at birth with either the features of
collodion membrane or
congenital ichthyosiform erythroderma. The diagnostic steps are based on clinical data, analyses such as the
steroid sulfatase activity test, skin biopsies, and genetic results. However, the dramatic increase in knowledge about the pathophysiology of these conditions has not led to a curative
therapy so far. The therapeutic management is multidisciplinary and involves
ichthyosis patient organizations in many countries. The mainstay of treatment remains with moisturizing creams containing, for example,
urea,
lactic acid and other
humectants and keratolytics, regular bathing, and mechanical scale removal. Patients with
lamellar ichthyosis or ichthyosiform
erythroderma in particular profit from oral
therapy with
retinoids or
retinoic acid metabolism-blocking agents.