itching and dermatitis
skin disorders
Itching
Not every episode of itching requires immediate evaluation by a doctor. The following information can help people decide whether a doctor's evaluation is needed and help them know what to expect during the evaluation. Most conditions that cause itching are not serious. The following may indicate that the cause could be serious: Weight loss, fatigue, or night sweats may indicate a serious infection or a tumor. Weakness, numbness, or tingling may indicate a nervous system disorder. Abdominal pain or a yellowish discoloration of the skin and eyes ( Jaundice in Adults ) may indicate a gallbladder or liver disorder. Excessive thirst, abnormally frequent urination, and weight loss may indicate Diabetes Mellitus (DM) . People who have weight loss, fatigue, or night sweats should see a doctor as soon as possible. People who have any of the other warning signs or severe itching should probably see a doctor immediately. Doctors ask many questions and look at the skin. Often, a person needs to undress so that the entire skin surface can be checked. If no clear cause is found after checking the skin, doctors may do a complete physical examination to check for systemic causes. Testing may be necessary to diagnose certain systemic causes and sometimes skin disorders. If itching is widespread and begins shortly after use of a drug or medication, that drug or medication may be the cause. If itching (usually with a rash) is confined to an area that was in contact with a substance, particularly if the substance is known to cause Contact Dermatitis , that substance is a likely cause. However, allergic causes of widespread itching can be difficult to identify because affected people have usually eaten several different foods and have been exposed to many substances that could cause an allergic reaction before itching develops. Similarly, identifying a drug that is causing the reaction in a person taking several drugs may be difficult. Sometimes the person has been taking the drug or medication causing the reaction for months or even years before a reaction occurs. Most causes of itching can be diagnosed without testing. If the diagnosis of a skin abnormality is not clear from its appearance and the person's history, removal ( Biopsy ) of a skin sample may be necessary so that it can be analyzed. If the cause of itching seems to be an allergic reaction but the substance causing the allergic reaction is not evident, skin testing may be necessary. In skin testing, substances that can cause allergic reactions on contact are applied to the skin in a patch (called Skin Tests ). If the cause seems not to be an allergic reaction or skin disorder, testing is done based on the person's other symptoms. For example, tests may be done for gallbladder or liver disorders, chronic kidney disease, thyroid disorders, diabetes, or cancer. 