Hyperimmunoglobulin E syndrome - Report of a rare case with review of literature

Dear Editor, A 5-year-old boy presented with a history of recurrent pyogenic infections involving the head and neck region since infancy.He had experienced three bouts of pneumonia, all of which were effectively treated with antibiotics.Clinical examination revealed characteristic facial deformity comprising a prominent forehead, broadened nasal bridge, sparse scalp hair, and slightly thick skin, along with scaling, papulopustular eruptions, and a few crusted erosions [Figures 1 and 2].His parents provided a surgical history of cervical lymph node excision subsequent to a cold abscess [Figure 3].There was no family history of similar illness or known consanguinity.Laboratory investigations demonstrated hemoglobin -11.2 g/dL, total leukocyte count -11,000/cumm (neutrophils 70% and eosinophils 11%), and a raised erythrocyte sedimentation rate.Notably, serum immunoglobulin E (IgE) levels were markedly elevated at 3289 IU/mL.Liver and renal function tests were within normal limits.Chest radiograph revealed bilateral patchy opacities, which were claimed to be remnants of previous pneumonic episodes by the pulmonologists.We made an orthopedic referral to screen for osteopenia, and no evidence of osteopenia was noted at this time.The clinical presentation and history of recurring infections, combined with markedly elevated IgE levels, were strongly suggestive of Autosomal Dominant Hyper-IgE syndrome (AD-HIES).A Signal Transducer and Activator of Transcription 3 (STAT3) mutation was considered likely, although genetic confirmation could not be done due to financial constraints.AD-HIES is typically caused by heterozygous mutations in the STAT3 gene on chromosome 17q21, leading to impaired Th17 differentiation, reduced neutrophil chemotaxis, and altered cytokine signaling, particularly interleukin (IL)-6 and IL-17 pathways.[1] Reduced interferon-gamma production in HIES contributes to elevated IgE levels by failing to suppress