Neutrophilic dermatoses, including Sweet's syndrome, have previously been recognized in antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis. Eosinophilic granulomatosis with polyangiitis (EGPA) is an ANCA-associated vasculitis. Vasculitis is inflammation of the blood vessels. SEE COMMENTS FOR INFO ON THESE CONDITIONS.
This is a case of a 46-year-old man with asthma who developed a fever, shortness of breath, difficulty moving about, and a severe rash. Skin lesions were on his scalp. Blood tests showed a raised white cell count, including a high eosinophil count (absolute eosinophil count 7.75), high-titer myeloperoxidase antibody (MPO-ANCA), and positive perinuclear ANCA (p-ANCA). CT scan demonstrated large subpleural opacities (lung involvement). Nerve conduction studies were consistent with peripheral neuropathy.
The findings were consistent with EGPA, but the rash wasn't typical of this condition - often subcutaneous nodules with eosinophilic vasculitis. The biopsy showed dense neutrophilic infiltrate with dermal oedema indicating Sweet's syndrome (lots of white blood cells called neutrophils in the tissue; fluid leaking into dermis; normally an absence of vasculitis).
The patient’s symptoms improved with intravenous methylprednisolone, followed by oral prednisone and rituximab.