- Typically presents with acute onset following vigorous exercise
- Most commonly involves the extremities: sleeve-like induration with a peau d'orange appearance
- Peripheral eosinophilia is often present.
- Some patients go on to develop a hematopoietic neoplasm.
- Lymphoplasmacytic inlammation of the fibrous trabeculae of the subcutaneous fat
- Progressive sclerosis of the fibrous trabeculae and subcutaneous fascia, eventually obliterating the fat lobules
- Similar features are present in morphea profunda and sleroderma, except the sclerosis is centered higher up, at the interface of the dermis and subcutis, rather than in the fascia.
- Additional changes that may sometimes be seen are tissue eosinophilia, mucin deposition and vasculitis.