Erysipelas () is a relatively common bacterial infection of the superficial layer of the skin (upper dermis), extending to the superficial lymphatic vessels within the skin, characterized by a raised, well-defined, tender, bright red rash, typically on the face or legs, but which can occur anywhere on the skin. It is a form of cellulitis and is potentially serious.Erysipelas is usually caused by the bacteria Streptococcus pyogenes, also known as group A β-hemolytic streptococci, through a break in the skin such as from scratches or an insect bite. It is more superficial than cellulitis, and is typically more raised and demarcated. The term is from Greek ἐρυσίπελας (erysípelas), meaning "red skin".In animals, erysipelas is a disease caused by infection with the bacterium Erysipelothrix rhusiopathiae. The disease caused in animals is called Diamond Skin Disease, which occurs especially in pigs. Heart valves and skin are affected. Erysipelothrix rhusiopathiae can also infect humans, but in that case, the infection is known as erysipeloid. Signs and symptoms
Symptoms often occur suddenly. Affected individuals may develop a fever, shivering, chills, fatigue, headaches, vomiting and be generally unwell within 48 hours of the initial infection. The red plaque enlarges rapidly and has a sharply demarcated, raised edge. It may appear swollen, feel firm, warm and tender to touch and may have a consistency similar to orange peel. Pain may be extreme.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).
There was no observable tolerance during a four weeks course of treatment with daily administration of oxcarbazepine or licarbazepine in electroshock test on mice and rats. Most of the antiepileptic activity can be attributed to licarbazepine. Aside from its reduction in side effects, it is presumed to have the same main mechanism as carbamazepine, sodium channel inhibition, and is generally used to treat the same conditions. Pharmacogenetics
The human leukocyte antigen (HLA) allele B*1502 has been associated with an increased incidence of Stevens–Johnson syndrome and toxic epidermal necrolysis in people treated with carbamazepine, and thus those treated with oxcarbazepine might have similar risks. People of Asian descent are more likely to carry this genetic variant, especially some Malaysian populations, Koreans (2%), Han Chinese (2–12%), Indians (6%), Thai (8%), and Philippines (15%). Therefore, it has been suggested to consider genetic testing in these people prior to initiation of treatment. Structure
Oxcarbazepine is a structural derivative of carbamazepine, with a ketone in place of the carbon–carbon double bond on the dibenzazepine ring at the 10 position (10-keto). This difference helps reduce the impact on the liver of metabolizing the drug, and also prevents the serious forms of anemia or agranulocytosis occasionally associated with carbamazepine. Aside from this reduction in side effects, it is thought to have the same mechanism as carbamazepine — sodium channel inhibition (presumed to be the main mechanism of action) – and is generally used to treat the same conditions. Oxcarbazepine is a prodrug which is activated to licarbazepine in the liver.