Heat rash is a skin disorder characterized by the formation of lumps or blisters that are itchy and result in prickly sensations. It commonly affects infants and children. However, adults can also be affected by heat rash, particularly during hot and humid weather. It is also called Miliaria.
When the sweat ducts are obstructed, it causes the perspiration to become trapped below the skin’s surface. This causes eventual development of heat rash resulting in occurrence of shallow lesions or deep, red bumps.
Most of the cases of heat rash fade away on their own without treatment. The patients are required to prevent increased buildup of sweat and lower the body and skin temperature to completely resolve the skin condition. However, severe cases of heat rash may need drug therapy.
Heat rash symptoms
- In adults, heat rash mostly affects the skin folds and other areas of the body where the skin tends to rub against clothing causing friction. It has a tendency to occur on the neck, chest and shoulders in a majority of infants. In few cases, heat rash may also appear on the elbow creases, groin and the armpits
The different types of heat rash and their associated symptoms are discussed below:
- Miliaria crystalline:
- It is the mildest form of heat rash and affects the sweat ducts occurring in the uppermost section of the skin
- It leads to the appearance of clear, small and superficial blisters. Occasionally, it may result in formation of tiny papules or bumps which easily rupture
- The blisters do not lead to itchiness or pain and tend to vanish on their own. However, the skin condition has a tendency to recur in hot and humid weather. Newborns are at an increased risk to developing this type of heat rash as opposed to adults
- Miliaria rubra:
- It appears in the deeper skin layers and usually affects the sweat glands occurring in the epidermis or the outer skin layer. This type of heat rash is commonly found to occur in individuals who have been bedridden for prolonged durations or those who have been chronically exposed to hot and humid conditions. Infants who are between the 1st and 3rd weeks post birth can also experience it.
- It may result in the formation of reddish bumps
- The affection skin areas may elicit extreme itchiness and prickly sensations
- There may be reduced or absent sweating of the affected regions
- Miliaria profunda:
- It is a rare type of heat rash and usually affects individuals suffering from chronic instances of miliaria rubra. It affects the dermis, which is a deeper layer of the skin. Activities that precipitate sweating like extreme physical exercising can increase the vulnerability to developing this form of heat rash.
- It causes formation of lesions that are similar in appearance to goose bumps, solid and skin-colored
- Reduced perspiration can lead to many abnormal symptoms of heat exhaustion like hypertension, rapid heartbeats, nausea, headaches and dizziness
Complications of heat rash include:
- Secondary infections of the heat rash lesions can result in fever; pus drainage from the bumps; chills; excessive pain; inflammation of the lymph nodes in neck, armpits and groin; swelling; redness; and warmth of the affected regions.
- Untreated heat exhaustion cases can result in a heat stroke
Causes of heat rash
Heat rash is caused due to clogging of the sweat ducts. The obstructed ducts prevent the evaporation of perspiration which become trapped below the skin’s surface, thereby causing skin inflammation and heat rash
The sweat ducts may become blocked due to the below listed reasons:
- The sweat ducts in newborns are immature and prone to easy rupture. This can then cause trapping of sweat under the skin. Infants kept in incubators, wrapped in heavy woolens, exposed to hot and humid conditions and those with high fevers are at increased risk to sweat gland rupture
- Blockage of skin pores due to excess use of skin creams and ointments
- Heavy physical activities or strenuous exercising can cause increased perspiration, blocking the sweat ducts and resulting in heat rash
- It can be a side effect of certain drugs used for treating ailments
- Topical or hot and humid weather conditions
- Use of several blankets or an electrical heater during winters can increase the vulnerability to developing heat rash
- The use of certain fabrics or tight apparels can prevent evaporation of perspiration
- Occasionally, heat rash may develop in hospitalized patients who are advised prolonged bed rest
Heat rash treatment
- One can prevent and alleviate cases of heat rash by restricting physical activities, wearing loose apparels, and cooling down the body by staying indoors in air-conditioned environments. This may also help in avoiding excessive perspiration
- Moderate cases of heat rash are treated with topical medications that reduce the itchiness and also work towards prevention of sweat duct obstruction
- Topical steroids are recommended to treat the most severe instances of heat rash
Heat Rash Pictures