Abstract: 【Abstract】 A 1-year and 9-month-old male proband presented with clustered rice-grain-sized flat smooth red papules distributed on the face, trunk and limbs for 1.5 years, without fever, joint swelling, or pain. The proband′s sister aged 7 years ever experienced swelling and pain in the finger joints of both hands at the age of 2 years, and had intermittent fever and papules all over the body at the same time, and the papules gradually regressed with the subsidence of fever. The proband′s mother aged 27 years suffered from swelling and pain in the finger joints of both hands when she was young, gradually leading to finger deformities, and developed intermittent knee swelling and pain at the age of 12 years without obvious skin lesions all over the body. No abnormality was found in ophthalmological and systemic physical examinations of the 3 patients. Whole-exome sequencing showed the proband, his sister and mother all had a heterozygous missense mutation c.1001G>A （p.R334Q） in exon 4 of the NOD2 gene. A diagnosis of Blau syndrome was made. The proband was treated with topical moisturizing cream all over the body; during the 52-week follow-up, no joint swelling and pain or eye symptoms were found in the proband, while erythema and depressed scars were observed on the face, trunk and limbs. The proband′s sister and mother were treated with subcutaneous injections of adalimumab at initial doses of 40 mg and 80 mg respectively, followed 1 week later by injections at 20 mg and 40 mg respectively, and then treated with injections at 20 mg and 40 mg respectively every 2 weeks; after 12-week treatment, the joint swelling and pain were markedly relieved in the proband′s sister and mother, and most skin lesions subsided in the proband′s sister; at week 52 during the follow-up, no joint swelling and pain or skin lesions were observed in the proband′s sister, and there was no swelling or pain in the knee joints of the proband′s mother, while no improvement was observed in her finger deformities. During the treatment, no eye symptoms or adverse reactions were observed neither in the proband′s sister nor in his mother.

Key words: Skin diseases, genetic, Therapy, Blau syndrome, NOD2 gene, Adalimumab