How are IgE and fatigue related?

The relationship between IgE and fatigue is indirect and not fully established. IgE is primarily involved in allergic responses (e.g., hay fever, asthma, food allergies). Chronic allergic inflammation can trigger systemic effects via cytokines (IL-4, IL-5, IL-13) and histamine release, potentially contributing to fatigue, brain fog, and reduced energy. However, fatigue is a highly nonspecific symptom with many possible causes (iron deficiency, sleep disorders, thyroid dysfunction, infections). Elevated IgE alone does not explain fatigue and must be interpreted in a clinical context. Evidence: mechanistic/unclear. Caveat: no direct causal link; individual assessment needed. Persistent fatigue with high IgE warrants medical evaluation (allergy testing, differential diagnosis).