Alopecia areata tied to various comorbidities
Alopecia areata (AA) is associated with a variety of comorbid conditions such as metabolic syndrome, iron deficiency anaemia and Helicobacter pylori infections, a recent meta-analysis has shown.
Applying the selection criteria yielded a total of 87 studies, four of which were cohort studies that focused on incident disease. Majority (n=83) investigated prevalent disease of either case-control (n=41) or cross-sectional (n=42) designs.
Atopic diseases were common AA comorbidities, with patients showing significantly elevated odds of having atopic dermatitis (odds ratio [OR], 2.36; 95 percent, 1.80–3.09) and allergic rhinitis (OR, 1.33; 1.19–1.47). Asthma showed prevalence that trended toward significance (OR, 1.11; 0.88–1.46).
Cardiovascular diseases also frequently occurred with AA. Hyperinsulinaemia (OR, 3.52; 1.43–8.71) and metabolic syndrome (OR, 3.68; 1.22–11.08) appeared to be more prevalent in AA patients, though data for these conditions came from only one small study. On the other hand, diabetes mellitus was significantly less likely to develop in AA patients (OR, 0.64; 0.57–0.73).
Other diseases significantly more prevalent in AA patients were H. pylori infections (OR, 2.03; 1.23–3.34), lupus erythematosus (OR, 4.73; 3.70–6.10) and incident autoimmune diseases (hazard ratio [HR], 1.86; 1.32–2.63) such as rheumatoid arthritis (HR, 1.79; 1.07–3.00), systemic lupus erythematosus (HR, 5.01; 2.08–12.05) and psoriasis (HR, 2.02; 1.06–3.83).
Anaemia (OR, 2.53; 1.45–4.40), particularly iron deficiency anaemia (OR, 2.78; 1.23–6.29), was also more common in AA patients, as was thyroid cancer (OR, 1.89; 1.53–2.34). Other solid organ malignancies showed weak correlations with AA.