Heat rash in newborns

Heat rash (prickly heat) in newborns

Prickly heat, or heat rash, is a small red rash that appears on an infant’s skin due to overheating. It is a very common condition, especially in warm weather or when the baby is bundled too tightly. It is not dangerous and usually resolves on its own once the cause of overheating is removed.

Why does prickly heat occur?

The newborn’s thermoregulatory system is still immature, and its sweat glands and ducts are very narrow. When the baby gets hot, it begins to sweat. If too much sweat is produced, or its evaporation is hindered by tight clothing, the sweat ducts can become blocked. Sweat that cannot reach the surface accumulates under the skin, causing irritation and the appearance of tiny red papules or vesicles.

Prickly heat most often appears in natural skin folds and where the skin sweats the most:

• Neck
• Armpits
• Groin area
• Upper back and chest

How to distinguish it from other rashes?

Prickly heat usually does not cause the baby significant discomfort, aside from mild itching. It differs from eczema in that the skin under the rash is not dry and rough. Unlike allergic rash, prickly heat is not associated with the introduction of new foods. Different types of rashes are described in detail in our blog "Rash in infants".

Prevention and care

The best remedies for prickly heat are coolness and fresh air. Dress the baby in lightweight natural‑fiber clothing, keep the room at a comfortable temperature (18‑22 °C), and provide frequent air baths. A warm‑water bath, possibly with added chamomile tea, can help soothe the skin. It is important to remember that overheating is a risk factor for sudden infant death syndrome, so proper temperature control is part of safe sleep.