Abstract: 【Abstract】 Objective To detect pathogenic gene mutations in a patient with CARD14-associated papulosquamous eruption （CAPE） and his family, and to observe the short-term and long-term efficacy and safety of ustekinumab treatment. Methods Clinical data were collected from a 6-year-old child presenting with erythroderma secondary to pityriasis rubra pilaris and his family members. Peripheral blood samples were collected from the patient, his parents and younger brother, and DNA was extracted from these peripheral blood samples. A next-generation skin-targeted sequencing panel was used to detect gene mutations, and Sanger sequencing was performed for verification. Genomic DNA was also extracted from 100 unrelated healthy controls using the same method. Results A heterozygous mutation c.349+1G>A in intron 6 of the CARD14 gene was identified in the proband and his mother, but was not identified in his father, younger brother or 100 healthy controls, leading to a diagnosis of CAPE in the proband. The patient received subcutaneous injections of ustekinumab at a dose of 45 mg at weeks 0 and 4, and every 12 weeks thereafter. After 1-week treatment, the skin lesions and symptoms improved markedly. No adverse events were reported during the 18-month treatment and follow-up. Conclusion The heterozygous mutation c.349+1G>A in the CARD14 gene may be the cause of the disease in this family, and ustekinumab was effective and safe for the treatment of CAPE.

Key words: Pityriasis rubra pilaris, CARD14-associated papulosquamous eruption, CARD14, Ustekinumab