Miliaria Rubra



  • Miliaria rubra is a papulovesicular eruption of eccrine sweat glands that often occurs in high heat and humidity.
  • Miliaria is also known as “sweat rash,” “prickly heat,” or “heat rash.”


It is very common and transient especially affecting neonates. However, both sexes and all age groups can be affected as well.


  • May be present in up to 4% of neonates with a mean age of 1 to 14 days
  • In tropical environment, as many as 30% of individuals exposed to heat may have miliaria.

Pediatric Considerations
More common in this age group

Etiology and Pathophysiology

Miliaria rubra is one of the different types of eccrine sweat duct occlusion. It occurs with the blockage of the duct within the epidermis. Leaking of sweat into this blocked duct causes periductal inflammation, formation of papules, leading to irritation and itching.

Risk Factors

The predisposing factors include hot and humid conditions, febrile illnesses, and occlusive clothing, dressing, or ointments (e.g., Aquaphor) (1).

General Prevention

  • Acclimatize slowly to hot weather.
  • Avoid hot and humid conditions.
  • Dress appropriately for warm environmental conditions.
  • Understand the self-limiting nature of the disease.

Commonly Associated Conditions

  • Exposure to hot and humid conditions
  • Neonates have immature eccrine glands, which rupture easily with sweating, resulting in miliaria.
  • Miliaria has been associated with a rare Morvan syndrome characterized by severe insomnia, for weeks or months in a row, and associated with autonomic alterations consisting of profuse perspiration (2).

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