What other conditions may mimic hives?
There are known skin problems that can be mistaken for hives. Some of these can include:
- Heat rash: When skin is exposed to very hot and often, humid weather conditions, sweat ducts can become blocked, forming fluid-filled blisters and bumps (accumulation of sweat, particularly in the folds of skin – in the groin, beneath the breasts, in the armpits or the inner thighs). These can be very sensitive to the touch and itchy. Friction caused by certain types of clothing can also aggravate these bumps, which range from mild to severe. Severe heat rash may result in bumps which affect the deeper layers of skin and fill with pus instead of a clear fluid. Heat rash can, however, also clear on its own once the trigger has been removed or if treated by cooling the skin down, reducing sweating, and restoring a normal internal body temperature.
- Contact dermatitis: A red rash develops following aggravating contact with the skin, such as an allergen substance. This could be an ingredient in a cream or make-up product, or metal found in jewellery, or detergent or soap. The sensation which occurs with contact dermatitis is usually more stinging or burning than an itch. A rash typically only occurs where contact with a trigger was made.
- Eczema: Red, inflamed, scaly, dry and itching skin are typical of an eczema breakout. Eczema can easily be confused with the physical characteristics of hives, as well as occur anywhere on the body. Exact causes of eczema are sometimes difficult to pinpoint, as is often the case with chronic hives. This skin condition, however, is often linked with an overactive immune system. Making an appointment with a dermatologist is best to diagnose eczema and treat it accordingly. Many treatments for hives will not be effective for an eczema breakout.
- Rosacea: This condition normally occurs on the facial area more than anywhere else on the body. A typical characteristic of rosacea is reddening of the cheeks, forehead, nose and chin. The condition also produces small pimple-like bumps and blood vessels, as well as watery eyes. Medications are the best course of treatment for this type of skin condition.
- Pityriasis rosea: A splotchy red rash can sometimes last for between 6 and 8 weeks (like a case of chronic hives) but can resolve on its own without any treatment at all.
A clue that a rash or marking may not be a case of mild or acute hives could be that it does not resolve within a 24-hour period. Another is if welts are filled with clear fluid, they are more likely hives.
Markings or bumps that are hard or filled with other materials, such as pus or are brownish in colour are often indicative of a more serious skin condition which will require medical diagnosis.