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Miliaria Rubra

para>More common in this age group ‚

ETIOLOGY AND PATHOPHYSIOLOGY

The rash is a result of keratinous plugging of the sweat ducts, which leads to swelling of the gland (known as a retention vesicle) and extravasation of sweat into the surrounding skin, leading to irritation and itching. ‚

RISK FACTORS

  • Hot, humid environment
  • Occlusive bandages/clothing (1)
  • High fever

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 are easy to rupture 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).

DIAGNOSIS

HISTORY

  • Lesions appear after person has been in a hot, humid environment that causes sweating.
  • Pruritus or prickly, mildly stinging sensation in affected body areas

PHYSICAL EXAM

  • Prevalent in areas of friction caused by clothing and in areas of flexure
  • Infants: trunk, diaper area, neck, axilla, face
  • Pilosebaceous follicles, palms, and soles are spared.
  • Fine papules and vesicles on an erythematous base (3)
  • May become inflamed pustules (miliaria pustulosa) (4)

DIFFERENTIAL DIAGNOSIS

  • Acne
  • Folliculitis
  • Viral exanthems
  • Drug eruptions
  • Erythema toxicum
  • Yeast skin infections
  • Pyogenic infections
  • Syringomas

DIAGNOSTIC TESTS & INTERPRETATION

Test Interpretation

  • Keratinous plugging of sweat ducts
  • Sweat-retention vesicle

TREATMENT

GENERAL MEASURES

  • Avoid wearing heavy, tight clothing or garments that may cause friction.
  • Avoid plastic or occlusive dressings/garments in hot environments.
  • Avoid excessive use of soap and contact with irritants.
  • Frequent cool baths with Aveeno colloidal, oatmeal, or cornstarch mixtures.
  • Provide cool, dry environment for 8 to 10 hours/day.
  • Topical application of lotions containing lanolin, calamine, boric acid, and menthol

MEDICATION

  • Topical lotions containing calamine, menthol, or camphor may be helpful for symptoms; over-the-counter preparations with menthol and camphor for pruritus: hydrocortisone (Cortaid) or pramoxine (Prax)
  • Topical steroids to relieve pruritus: 2.5% hydrocortisone (Hytone) BID as needed for 2 to 3 days or 0.1% betamethasone (Valisone) BID as needed for 2 to 3 days; avoid prolonged usage.
  • Rarely, systemic antibiotics in cases of bacterial secondary infection: antibiotic effective against staphylococci (e.g., dicloxacillin 250 to 500 mg QID for 10 days unless strain is resistant to agent)
  • If sweating is secondary to fever, then antipyretic drugs may be useful.
  • Precautions: Care should be taken with fluorinated steroid application in children. These agents may cause systemic effects.

COMPLEMENTARY & ALTERNATIVE MEDICINE

  • Use of tannic acid has not been shown to be effective.
  • Aloe vera gel may be effective for heat-related rashes.
  • Oatmeal bath may help with the itching associated with miliaria (5).

ONGOING CARE

FOLLOW-UP RECOMMENDATIONS

Avoid vigorous activity that causes excessive sweating. ‚

PROGNOSIS

  • Benign: responds to cooling
  • Avoiding causative agents is key.

COMPLICATIONS

  • Secondary bacterial infections
  • Miliaria profunda secondary to repeated miliaria rubra can cause anhidrosis.

REFERENCES

11 Carter ‚ RIII, Garcia ‚ AM, Souhan ‚ BE. Patients presenting with miliaria while wearing flame resistant clothing in high ambient temperatures: a case series. J Med Case Rep. 2011;5:474.22 Tabanelli ‚ M, Passarini ‚ B, Liguori ‚ R, et al. Erythematous papules on the parasternal region in a 76-year-old man. Clin Exp Dermatol. 2008;33(3):369 " “370.33 Gan ‚ VN, Hoang ‚ MP. Generalized vesicular eruption in a newborn. Pediatr Dermatol. 2004;21(2):171 " “173.44 Haas ‚ N, Martens ‚ F, Henz ‚ BM. Miliaria crystallina in an intensive care setting. Clin Exp Dermatol. 2004;29(1):32 " “34.55 Reynertson ‚ KA, Garay ‚ M, Nebus ‚ J, et al. Anti-inflammatory activities of colloidal oatmeal (Avena sativa) contribute to the effectiveness of oats in treatment of itch associated with dry, irritated skin. J Drugs Dermatol. 2015;14(1):43 " “48.

CODES

ICD10

L74.0 Miliaria rubra ‚

ICD9

705.1 Prickly heat ‚

SNOMED

  • Prickly heat
  • Miliaria rubra, infantile (disorder)

CLINICAL PEARLS

  • Miliaria is most common in the pediatric age group.
  • Topical mild steroid creams may be used to reduce symptoms.
  • Avoiding hot and humid temperature is helpful in prevention and treatment.