Miliaria rubra, also known as heat rash

Author: V. Dimov, M.D., Allergist/Immunologist and Assistant Professor at University of Chicago
Reviewer: S. Randhawa, M.D., Allergist/Immunologist and Assistant Professor at NSU

A 3-month-old girl is at the allergy clinic for evaluation of rash. She has had recurrent erythematous macular rash (1-2 mm in size) affecting his chin, below chin area, back of the neck and extremities. She is breastfed. She also has episodic nasal congestion.

Family Medical History: Father with allergic rhinitis.

Social History: They have a pet cat.

Physical Examination: Skin: macular rash (1-2 mm in size) affecting his below chin area, and back of the neck (3-4 lesions in each area).

What is the likely diagnosis?

Miliaria rubra.

Family is interested in allergy testing. Percutaneous skin testing with indoor, outdoor, and food allergens is negative. Airborne allergens: Negative for Dust mite, Cat, Dog, Cockroach, Mold mix with 10 molds. Food allergens: Negative for Tree nuts, Egg, Milk, Peanut, Soy, Wheat, Fish, Shellfish.

Miliaria rubra is also known as heat rash. No evidence of atopic or seborrheic dermatitis at this time. No evidence that food or airborne allergens play a role in the rash. Skin testing has approximately 30% better sensitivity than serum IgE (Cleveland Clinic J of Med, 2011, 78-9), and a negative skin test typically rules out environmental or food sensitization in approximately 90% of patients.

What would you recommend for treatment of miliaria rubra, also known as heat rash?

Regarding Miliaria rubra, avoidance of overheating, removal of excess clothing, cooling baths, and air conditioning are recommended for management and prevention of these related disorders.

For mild exacerbations, they can try topical hydrocortisone 1% for up to 1-3 weeks.

References

The Generalized Rash http://buff.ly/1nvYMGM and http://buff.ly/1n61l48 - 2 part series from Am Fam Physician (PDF)

Newborn Skin: Common Rashes and Birthmarks http://buff.ly/1nvYXSI and http://buff.ly/1nvZ68C - 2 part series from Am Fam Physician (PDF)


Published: 05-12-2013
Updated: 05-28-2014