Familial eosinophilic cellulitis is a rare skin disorder. It sometimes occurs as an exaggerated response to bites of spiders, bees, fleas, ticks, or mites (arthropods), or it may have other causes such as surgery or drugs. The skin of the person will develop flame shaped patterns of raised, swollen, red areas that are warm to the touch. The episodes usually come on rapidly. Often, familial eosinophilic cellulitis will recur suddenly over a period of years with Swelling and Redness developing for no apparent reason. The attack may last up to six weeks and may continue to recur for years.
Large areas of skin may be affected and testing shows microscopic changes of the tissue. An abnormal number of white blood cells (eosinophils) are found in the red and swollen areas of skin, underlying fat, and usually in the blood. Skin Blistering has also been known to develop.