Ingredients in perfume or nickel exposure can also produce the characteristic rash. Urticaria occurs when histamine and other chemicals are released from under the skin's surface, causing the tissues to swell. Triggers  sometimes include: ACE inhibitors that are often used to treat high blood pressure (hypertension) can be linked to deeper swellings of angioedema. Even alterations in the physical environment can produce nettle rash, such as exposure to the sun, physical pressure on the skin, or changes in body temperature. The skin surrounding the hives may be red. During the duration of this condition (also known as hives, nettle rash, or welts), the child suffers from intense itchiness. You should also be referred to a dermatologist if you just have chronic urticaria and the symptoms continue, despite treatment. Some sexually transmitted infections may result in bumps, blisters, or a rash on the genitals. The triggers of acute urticaria are unknown in around half of all cases. You should also contact your GP if your symptoms are: Acute urticaria (also known as short-term urticaria) is a common condition, estimated to affect around one in five people at some point in their lives. These could be signs of a severe allergic reaction, such as anaphylactic shock. A rash can be local to just one small part of the body, or it can cover a large area. See how you react to the antihistamine before driving or operating heavy machinery. Around a quarter of people with acute urticaria and half of people with chronic urticaria also develop angioedema, which is a deeper swelling of tissues. However, this is difficult to diagnose and the treatment options are the same. The Allergy UK website has more information on: Avoiding or cutting down on foods that contain these chemicals may improve your symptoms. So what triggers the release of histamines? Children are often affected by the condition, as well as women aged 30 to 60, and people with a history of allergies. If you have chronic urticaria and angioedema, you may be referred to a skin specialist (dermatologist). Corticosteroids suppress your immune system, which lessens the symptoms of urticaria. They can appear on any part of your baby's body, usually after contact with some kind of trigger, such as an allergen or illness (Saini 2018). Your GP can usually diagnose acute urticaria by examining the rash. The rash is usually very itchy and ranges in size from a few millimetres to the size of a hand. Ringworm is responsible for "athlete's foot" and "jock itch." A course of prednisolone lasting between three and five days is usually recommended. If your symptoms are very severe, your GP may prescribe other medications, such as a short course of corticosteroid tablets. These include: Your GP will usually be able to diagnose urticaria by examining the rash. If your symptoms are troublesome or persistent, antihistamines are available over the counter from pharmacies. It may appear on one part of the body or be spread across large areas. Possible side effects of corticosteroid tablets include: Long-term use of corticosteroids for chronic urticaria isn't recommended for the reasons mentioned above. Tell the operator about your (or their) symptoms. Allergy testing may be needed to find out if you're allergic to suspected triggers for urticaria. Urticaria can be one of the first symptoms of a severe allergic reaction known as anaphylaxis. Urticaria : Nettle rash (also known as urticaria) is composed of reddish itchy weals or swellings in the skin similar to those resulting from contact with stingin ... Read More 2 doctors agree Hives rashes usually settle down within a few minutes to a few days. Another herbal remedy to prevent and treat hives is stinging nettle (Urtica dioica). The rash is often itchy and sometimes feels like it's stinging or burning. While about 20 percent of people experience it, the rash is not contagious and most likely linked to an allergic reaction, infection, or chronic illness. The weals are swellings of the upper skin layer measuring a few millimetres to a few centimetres. 3. In around two-thirds of cases, a powerful medication called ciclosporin has proved effective in treating urticaria. This is known as an autoimmune reaction. In the last third no cause is found., The cause of the rash is not known in more than half of cases and it is commonly a one-off event. Living with itchy skin can be particularly upsetting. If you have persistent urticaria, you may be referred to a skin specialist (dermatologist). Causes of Stinging nettle rash. They also may not be suitable for young children. Although the affected area may change in appearance within 24 hours, the rash usually settles within a few days. Call 999 immediately and ask for an ambulance if you or someone else is experiencing anaphylaxis. H2 antihistamines can sometimes be useful for treating chronic urticaria, because they narrow blood vessels, which can reduce the skin's redness. Side effects, such as high blood pressure and high cholesterol, are a particular cause for concern, because they can increase your risk of heart disease and stroke. You may be prescribed a short course of high-dose corticosteroid tablets, such as prednisolone, if your symptoms are severe. Your GP can prescribe this. Certain triggers may also make the symptoms worse. They include headaches and nausea (feeling sick). Next review due: 6 February 2021, your hives keep coming back – you may be allergic to something, you also have a high temperature and feel generally unwell, you also have swelling under the skin – this might be, rapid and severe swelling of the face, mouth or throat, heat – work and sleep in a cool room and wear loose, lightweight clothes, medicines – speak to a GP if you have an allergic reaction. A short course of steroid tablets (oral corticosteroids) may occasionally be needed for more severe cases of urticaria. There are 3 distinct types of urticaria: Acute urticarial lasts between several hours up to 6 weeks. A rash that includes redness, itching, and inflammation may persist since the skin has been injured from the direct contact from the stinging nettle plant. Viral rashes in young children are common. If your symptoms are troublesome or persistent, antihistamines are available over the counter from pharmacies.