Abstract: Objective: To report a case of atopic dermatitis (AD) presenting with generalized follicular keratotic papules and chronic pruritus, to identify the potential pathogenic gene. Methods: Clinical data of the proband were collected and peripheral blood DNA was obtained from the proband and his parents. Targeted exome sequencing of genes related to hereditary skin disorders was performed, followed by Sanger sequencing validation. The pathogenicity of the variant was evaluated based on variant type, population databases, in silico prediction tools and published evidence. Results: The proband was a 13-year-old male who had suffered from generalized keratotic follicular papules, xerosis and pruritus all over the body for 10 years. His peripheral blood eosinophil count and IgE level were elevated; allergen screening in another hospital indicated wheat bran allergy, and he had a history of allergic rhinitis and wheat flour allergy, with no similar diseases reported in his family. A heterozygous c.89G＞A (p.Arg30Gln) variant in the CARD11 gene was detected in the proband, and confirmed as a de novo variant by Sanger sequencing and segregation analysis. Conclusion: This study reports a case of atopic dermatitis clinically featured by generalized keratotic follicular papules, which enriches the clinical phenotypic spectrum of CARD11 variants.

Key words: CARD11 gene, atopic dermatitis, primary immunodeficiency