What is miliaria? Miliaria is a very common skin condition in newborns. The pores of their immature sweat glands plug easily, leading to tiny pink bumps or water blisters. Who gets miliaria? Miliaria is most common in the first few weeks of life. It is especially common in hot, humid weather but almost any baby can get it. It is more common in babies who are bundled too warmly. Older children and adults can also get miliaria, in which case it is often called “prickly heat.” What are the symptoms of miliaria? There are two common types of miliaria. The plugged pores of miliaria crystallina result in pinpoint sweat blisters with no redness. The plugged pores of miliaria rubra (prickly heat) produce small red bumps, with or without sweat blisters. Either way, miliaria tends to show up on covered parts of the skin, especially where there is friction from clothing. The forehead (under caps or visors), body folds, the upper back and chest, and the arms are the most common locations. Often prickly heat itches in older children, and they often describe a ‘prickly’ sensation. What newborns feel remains a mystery. The prickly heat rash can look quite similar to one caused by infected hair follicles (folliculitis), but if you look at the prickly heat bumps with a magnifying glass, no hair follicles will be seen. An important note: Fever can produce prickly heat, but is not caused by it – if your child has a fever, you still need to find the cause. 1. See Also 1. Newborn Skin Exam 2. Pathophysiology 1. Sweat retention when Eccrine Glands partially close 2. Similar pathophysiology to Milia, but these 2 conditions are not the same 3. Epidemiology 1. Incidence : 40% of newborns 4. Types: Common 1. Milia ria crystallina (Miliaria alba, miliaria sudamina) 1. Sweat infiltrates below Stratum Corneum 2. Vessicles 1-2 mm without surrounding erythema on head, neck and trunk 1. Noninflammatory Vesicles resemble water droplets 2. Each vessicle ruptures and then desquamates and resolves within days 2. Milia ria rubra (heat rash, default type of miliaria) 1. Sweat infiltrates deeper, below Epidermis 1. Inflammation associated with Sweat Gland obstruction 2. Pruritic erythematous Papules and Vesicles on covered (over- heated) skin 5. Types: Other 1. Apocrine miliaria (Fox-Fordyce Disease) 2. Milia ria profunda 1. Limited to hot, humid climates 2. Follows severe miliaria rubra 6. Signs 1. Papulovesicular lesions 2. Distributed in intertriginous areas and occluded areas 7. Differential Diagnosis 1. See Neonatal Pustules and Vessicles 8. Management 1. Resolves spontaneously in first few months of life 2. No treatment is needed 3. Avoid Occlusion and excessive heat 1. Avoid over-dressing 2. Consider cool baths (avoid prolonged exposure due to Hypothermia) 3. Stay in cool air conditioned environments 9. References 1. Feng (1995) Cutis 55:213 2. O'Connor (2008) Am Fam Physician 77:47 Fox Fordyce disease (C0016632) Definition Chronic pruritic disease, usually in women, characterized by small (MSH) follicular papular eruptions in apocrine areas. It is caused by obstruction and rupture of intraepidermal apocrine ducts. (From Dorland, 27th ed) Concepts Disease or Syndrome (T047) ICD9 705.82 MSH D005588 Apocrine miliaria, Chronic itching papular eruption of axillae and English pubes, Chronic itching papular eruption of axillae AND/OR pubes, FOX FORDYCE DIS, Fox Fordyce Disease, Fox-Fordyce Disease enfermedad de Fox - Fordyce, erupcion papulosa pruriginosa cronica Spanish de axila y pubis, erupcion papulosa pruriginosa cronica de axila Y/O pubis, miliaria apocrina Other specified sweat gland disorders (C0157735), Miliaria Parent (C0026113), Disorder of apocrine gland (C0406488), Duplicate concept Concepts (C1274013) DXP, ICD9CM, MSH, MTH, NDFRT, SCTSPA, SNOMEDCT Sources Derived from the NIH UMLS (Unified Medical Language System) Miliaria (C0026113) A syndrome of cutaneous changes associated with sweat retention and extravasation of sweat at different levels in the skin. Miliaria rubra, or Definitio prickly heat, results from apocrine duct obstruction. The sweat then n (MSH) seeps into the epidermis, producing pruritic erythematous papulovesicles. (From Dorland, 27th ed) Concepts Disease or Syndrome (T047) MSH D008883 English Miliaria Spanish miliaria Sweat Gland Diseases (C0038986), SKIN INFECTION/INFLAMMATION Parent (C0549663), Syndrome (C0039082), Disease of Skin and Appendages Concepts (C0037272), skin disorder (C0037274), Duplicate concept (C1274013) COSTAR, CSP, CST, MSH, MTH, NCI, NDFRT, SCTSPA, SNOMEDCT Sources Derived from the NIH UMLS (Unified Medical Language System) Miliaria Rubra (C0162423) Concepts Disease or Syndrome (T047) ICD9 705.1, 705.1 MSH D008883 Heat rash, Miliaria crystallina, Miliaria Rubra, Miliaria tropicalis, Prickly English Heat, Prickly heat - miliaria, Sudamina, Sweat rash miliaria cristalina, miliaria rubra, miliaria tropical, rash por calor, Spanish salpullido por calor, sarpullido por calor, sudamina Sweat Gland Diseases (C0038986), Miliaria (C0026113), Skin disorder Parent due to physical agent AND/OR foreign substance (C0458392), Concepts Ambiguous concept (C1274012), Duplicate concept (C1274013) COSTAR, ICD9CM, MSH, MTH, MTHICD9, SCTSPA, SNOMEDCT Sources Derived from the NIH UMLS (Unified Medical Language System) Miliaria profunda (C0263468) Concepts Disease or Syndrome (T047) English Miliaria profunda Spanish miliaria profunda Parent Miliaria (C0026113), Duplicate concept Concepts (C1274013) SCTSPA, SNOMEDCT Sources Derived from the NIH UMLS (Unified Medical Language System) .