Acute febrile neutrophilic dermatosis is a skin condition characterized by fever, inflammation of the joints (arthritis), and painful skin lesions that appear mainly on the face, neck, back and arms. Although middle-aged women are most likely to develop this condition, it may also affect men, older adults and even infants. The exact cause of Acute febrile neutrophilic dermatosis often isn't known. It is suspected that it can be a reaction of the body to certain exposures (sun), infections (Streptococcus bacteria, Campylobacter), or medications (azathioprine, nonsteroidal anti-inflammatory medications). This condition can also occur with some types of cancer and other serious health problems.