Miliaria



Miliaria


Preston W. Chadwick and Warren R. Heymann


Evidence Levels:  A Double-blind study  B Clinical trial ≥ 20 subjects  C Clinical trial < 20 subjects  D Series ≥ 5 subjects  E Anecdotal case reports


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Miliaria is a benign, transient disorder caused by occlusion in the eccrine duct. It is subdivided into miliaria crystallina, miliaria rubra, and miliaria profunda, based on the level of obliteration. Miliaria crystallina, the most superficial form (sudamina), occurs with occlusion of the sweat duct in the stratum corneum. It is self-limiting and typically appears as clear vesicles without significant erythema. Miliaria rubra (‘prickly heat’) is the most common, presenting as numerous pruritic non-follicular papules or vesicles with surrounding erythema. The obstruction occurs within the eccrine duct in the stratum malpighii. Typically it occurs on the trunk, neck, or back, but can affect other areas and has been reported to occur under splints or braces and military uniforms because of the warm occlusive environment. Miliaria profunda is more uncommon, the occlusion occurring at the dermoepidermal junction or dermis. Miliaria profunda is typically seen after repeated cases of miliaria rubra in tropical settings. These patients can also have associated systemic symptoms related to overheating.



Management strategy


Miliaria most typically occurs as a result of excessive sweating in hot, humid conditions, prolonged perspiration, or following extended febrile illness. There are other less common reports of congenital miliaria, miliaria occurring after medication administration in the intensive care setting, and in association with congenital illnesses such as pseudohypoaldosteronism. Miliaria is often exacerbated by tight clothing and high humidity. Management begins with removal of the inciting factors. There is no strong evidence for the various treatment options.


Adults often develop miliaria during travel in the tropics, military service or with heavy exercise. Gradual exposure helps to acclimatize to a hot and humid environment, but this may take a few months. Loose-fitting clothing, fans and cool showers may minimize the symptoms. With the use of any topical lotion or cream, care must be taken to ensure that the product applied does not occlude the skin, further exacerbating the condition. In the case of severe itching, antihistamines, cold packs, and topical corticosteroids may be used. Oatmeal baths have been anecdotally reported to provide relief. However, all these measures will prove ineffective if the sweating is not reduced. All cases will respond to air-conditioning, exposure of the involved skin, and the use of antipyretics, in appropriate circumstances. Miliaria profunda has been reported to respond to oral retinoids and anhydrous lanolin.


Miliaria may be complicated by superinfection; it should be treated with systemic antibiotics aimed at staphylococci as the likely pathogen. Clinicians should make patients aware that anhidrosis in the area of the eruption may occur and persist up to 3 weeks (or sometimes even longer) after the onset of lesions, and increased heat retention may occur if a large surface area was initially affected. Thus, patients at risk of heat exhaustion or heat stroke should take precautions to remain in air-conditioned environments during hot weather. A biopsy may be helpful in atypical cases of miliaria.



Specific investigations









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Aug 7, 2016 | Posted by in Dermatology | Comments Off on Miliaria

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