Eyelash length for the diagnosis of atopic dermatitis and ichthyosis vulgaris in children-a case control study.

Eyelash trichomegaly (ET) is increased length (≥ 12 mm), curling, pigmentation, or thickness of eyelashes. Among acquired causes, allergic diseases and atopic dermatitis (AD) have been found to be associated with eyelash trichomegaly especially in children; however, to date, this claim has not been studied in detail. To compare the eyelash lengths of AD and ichthyosis vulgaris (IV) patients with those of age- and sex-matched patients with unrelated skin disorders, we measured (with a digital Vernier caliper) and compared the eyelash lengths of AD (n = 58) and IV (n = 31) patients to those of age- and sex-matched patients with unrelated skin disorders (n = 178). The eyelashes of the AD and male IV patients were found to be significantly longer than those of the controls (p < 0.05). The severity of atopic dermatitis, i.e., SCORAD of > 50, hyperlinearity of palms and soles, and high IgE levels significantly correlated with the long eyelashes. The limitations of study are single-center study and filaggrin gene mutation in patients of IV could not be studied.

CONCLUSION: Thus, long eyelashes may act as surrogate marker of severe AD and serve as a cutaneous marker of IV patients. What is Known: • Among acquired causes, allergic diseases and atopic dermatitis have been found to be associated with eyelash trichomegaly especially in children. What is New: • The severity of atopic dermatitis, i.e., SCORAD of > 50, hyperlinearity of palms and soles, and high IgE levels significantly correlate with the long eyelashes; thus, long eyelashes may act as surrogate marker of severe atopic dermatitis. • It may also serve as a cutaneous marker of ichthyosis vulgaris especially in male patients and patients with palmoplantar hyperlinearity.