[1][2][3] Erysipelas is usually caused by the bacterium Streptococcus pyogenes, also known as group A β-hemolytic streptococci, which enters the body through a break in the skin, such as a scratch or an insect bite.

Affected individuals may develop a fever, shivering, chills, fatigue, headaches and vomiting and be generally unwell within 48 hours of the initial infection.

[4][7] It may appear swollen, feel firm, warm and tender to touch and have a consistency similar to orange peel.

[7] More severe infections can result in vesicles (pox or insect bite-like marks), blisters, and petechiae (small purple or red spots), with possible skin necrosis (death).

[8] The infection may occur on any part of the skin, including the face, arms, fingers, legs and toes; it tends to favour the extremities.

[7] The infecting bacteria can enter the skin through minor trauma, human, insect or animal bites, surgical incisions, ulcers, burns and abrasions.

There may be underlying eczema or athlete's foot (tinea pedis), and it can originate from streptococci bacteria in the subject's own nasal passages or ear.

[10] Erysipelas is usually diagnosed by the clinician looking at the characteristic well-demarcated rash following a history of injury or recognition of one of the risk factors.

[2] Tests, if performed, may show a high white cell count, raised CRP or positive blood culture identifying the organism.

[11] Erysipelas must be differentiated from herpes zoster, angioedema, contact dermatitis, erythema chronicum migrans of early Lyme disease, gout, septic arthritis, septic bursitis, vasculitis, allergic reaction to an insect bite, acute drug reaction, deep vein thrombosis and diffuse inflammatory carcinoma of the breast.

[21] Erysipelas caused systemic illness in up to 40% of cases reported by UK hospitals and 29% of people had recurrent episodes within three years.