PMC8170136_01
(A) Vesiculo-pustular rashes on the trunk of this patient before treatment; (B) Rashes on the trunk of this patient after treatment; (C) Pedigree of the patient. The arrow indicates the proband. The asterisks indicate the individuals who carried c.505A > G (p. I169V) mutation in the exon 6 of the PLCG2 gene and presented with high immunoglobulin E; (D) Sanger sequencing result of the PLCG2 gene from the proband and his father; (E) Sequence alignment of PLCgamma2 protein among various vertebrates.
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At the age of 14 years, painless and non-itching vesiculopustular rashes were noticed all-over his body (Figure 1A), which lasted about 2 to 3 weeks. He denied family history of autoinflammatory diseases (Figure 1C). Whole exome sequencing identified a novel paternal heterozygous missense mutation in exon 6 of the PLCG2 gene c.505A>G, p.Ile169Val, which is a highly conserved residue (Figures 1D, E). He was treated with prednisone 30 mg per day, methotrexate 12.5 mg per week and intravenous immunoglobulin (IVIG) 20 g per day once for 3 days every 3 months, with a satisfactory response for the fever, rashes (Figure 1B), bronchitis and headache.
Skin lesion and arthritis of the Chinese patient with APLAID. (A) The lump under the left knee; (B, C). The ulceration which was diagnosed as gangrenous pyoderma got worse. (D) Ulceration healing after dressing changing and adalimumab treatment. (E) Bone marrow erosion of the knee on MRI. (F) Skin biopsy of the ulceration. The arrow indicates perivascular lymphocyte infiltration.
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He remained stable with only regular IVIG infusion for 6 months, when he noticed pitting edema in his left lower limb, followed by two lumps in his left leg and knee arthritis (Figure 2A). Two weeks later, the lumps got postulated with reddish-swelling, ulceration and effusion (Figure 2B). Antibiotics were ineffective, pustules and arthritis got worse (Figure 2C). MRI revealed increased bone marrow edema, joint fluid and soft tissue effusion around the knee (Figure 2E). Skin biopsy showed massive perivascular lymphocyte infiltration without signs of infection or lymphoma (Figure 2F). After the first dose, gangrenous pyoderma had greatly improved (Figure 2D) and CRP decreased to 6.19 mg/dl.