Rare autoimmune disease takes nearly 5 years to diagnose — and women wait even longer

A rare autoimmune condition called eosinophilic granulomatosis with polyangiitis (EGPA) is taking far too long to diagnose — nearly 5 years on average, according to a new study published in Allergy. Researchers at Thomas Jefferson University Hospital analyzed 36 adults with EGPA and found that almost half waited more than 3 years from symptom onset to confirmed diagnosis. The disease's rarity and its tendency to affect multiple organs — including the lungs, sinuses, skin, and heart — make it easy to miss or misattribute to other conditions like asthma or chronic rhinosinusitis.

The study also uncovered a troubling gender gap: women faced nearly 7 times higher odds of experiencing a diagnostic delay of more than 3 years compared to men. Prior use of biologics (like mepolizumab or dupilumab) was also linked to longer delays, possibly because these treatments can mask EGPA symptoms.

Key Takeaways:

• Average time from symptom onset to EGPA diagnosis: 4.82 years
• Women had 6.7x higher odds of a delay >3 years vs. men (OR = 6.7; P = .01)
• Prior biologic use was associated with 7x higher odds of diagnostic delay
• 97% of patients had elevated eosinophil counts (>300 cells/μL) at diagnosis
• 42% presented with severe disease at the time of diagnosis

Why it matters: EGPA is a serious, potentially life-threatening condition, and delayed diagnosis means more patients arrive with severe disease already underway. Clinicians should maintain a high index of suspicion — especially in women and biologic-treated patients — when faced with treatment-resistant airway disease, marked eosinophilia, or unexplained organ involvement.