Sweet syndrome (acute febrile neutrophilic dermatosis)
= tender, red-to-purple papules and nodules + fever + peripheral neutrophilia
The skin lesions display pathergy or Köebner phenomenon – lesions occur in areas of minor trauma, such as sites of scratches, bites
It is usually preceded by an URTI, vaccination or GIT infections, but can also occur secondary to medications and in pregnancy. Frequently associated with underlying malignancy (especially haematological) or other immunodeficiency – occurrence of Sweet syndrome should prompt workup for underlying cause.
Steroids are very effective for the skin lesions, but the underlying cause should be treated as well.