Red blotches on your stomach may form when your body releases histamines. Your body releases histamines when you are exposed to allergens. Histamines attach to your cells and cause them to swell and leak fluid. This can cause allergic reactions like red blotches on your stomach. See your doctor any time unexplained changes occur on your skin or if the condition gets worse.
Hives and Erythema multiforme may produce a red blotchy rash on your stomach. Hives usually result from allergens that trigger the release of histamines that can form red blotches on your abdomen . Erythema multiforme is a skin disorder that is may also result from an allergic reaction to certain viruses or drugs.
Hives are red or white raised welts may vary in size and may appear on your abdomen. You may develop a single welt or several welts. Hives may seem to move because welts may disappear as new welts form. Hives may burn or itch severely. Persistent or more severe cases of hives may accompany difficulty breathing, loss of consciousness or anaphylactic shock. Red blotches associated with erythema multiforme may be flat or raised and range in size from less than 0.5 inch to more than 4.0 inches wide. These blotches may be symmetrical and have a central lesion surrounded by lighter red rings.
Hives are normally caused by an allergic reaction to foods, medications and other allergens. According to MayoClinic.com, shellfish, fish, nuts, eggs, chocolate and milk are common causes of hive breakouts. Common drugs that cause hives are penicillin, aspirin, ibuprofen and blood pressure medications. Hives can also result from emotional stress, excessive sweating and extreme cold or sun exposure. Erythema multiforme results from allergic reactions that may be caused by infections or medications. Some medications that can cause erythma multiforme are barbiturates, penicillins, phenytoin and sulfonamides. Mycoplasma or variations of the herpes simplex virus may also lead to erythema multiforme.
You can treat mild hives with over-the-counter antihistamines. These medications stop the histamine reaction that causes hives, diphenhydramine, chlorpheniramine, loratadine and cetirizine, and affective against mild hives. According to MedlinePlus, treatment of erythma multiforme focuses on controlling the illness that cased the condition, preventing more infections and treating the symptoms. You can treat mild cases of erythma multiforme with antihistamines and a moist compress to help reduce itching. You can take over-the-counter fever reducers, such as acetaminophen, to reduce fever that may accompany the condition. Topical anesthetics that help reduce pain or discomfort on your skin that results from erythma multiforme.
Your doctor may prescribe desloratadine, fexofenadine, hydroxyzine or levocetirizine for more severe or persistent cases of hives. Severe cases of erythma multiforme may require prescription medications, including antibiotics, that help control skin infections. Corticosteroids can help control swelling that may occur with erythma multiforme. Itravenous immunoglobulins may stop the disease process and especially severe erythma multiforme may require hospitalization, intensive care or burn care.