Prickly heat or heat rash describes a cluster of small itchy red blisters across the skin that cause a burning or prickling sensation. Also known of as miliaria, the rash occurs as a result of blocked sweat glands. Obese and overweight individuals are susceptible to prickly heat as are babies and small children due to their under developed sweat glands.
Symptoms of prickly heat
Some of the clinical features of prickly heat are:
The rash commonly develops across the face, neck, chest and back but may also develop in the genital folds, armpits and back of the thighs
The rash causes skin to feel rough with an itching, burning, stinging or prickling sensation
Sometimes the rashes may acquire a secondary bacterial infection that may give rise to painful lesions filled with pus
Causes of prickly heat
Prickly heat occurs more commonly during the summer and in hot and humid climates, especially among individuals who tend to sweat more. Sweat gets trapped underneath the skin and leads to the local irritation and inflammation that causes the rash. Pockets of trapped sweat may also burst releasing sweat that then comes into contact with the red and inflamed skin and causes stinging.
Diagnosis and treatment of prickly heat
Prickly heat is diagnosed by a clinical examination of symptoms and the appearance and distribution of the rash across the body. The condition does not usually require any treatment, often resolving on its own within a few days. However, some measures that may be taken to help the rash clear are:
Avoiding exposure to heat by staying indoors and in an air conditioned environment
Wearing loose cotton clothes and undergarments
Taking regular baths in cool water and using soap to remove any accumulated sweat and grime
Applying calamine-containing lotions to soothe affected areas
In severe cases, steroid-containing creams and lotions may also be recommended
Reviewed by Sally Robertson, BSc