Miliaria rubra (heat rash)
Overview
- Obstruction level: acrosyringium in the stratum spinosum / granulosum (epidermal portion of the duct).
- Clinical: densely grouped, intensely red 1–3 mm papules / papulovesicles on an erythematous base, non-follicular, with marked pruritus, prickling, burning („prickly heat").
- Localization: covered trunk, neck, forehead, intertriginous areas — typically sparing of face, palms, soles.
- Triggers: travellers to hot-humid tropics develop lesions within days to weeks; in Central Europe in obese patients with exertional hyperhidrosis, in infants in the diaper area, in bedridden adults under occlusive bedding.
- Complication: extensive involvement → anhidrosis with heat intolerance up to tropical anhidrotic asthenia / heat stroke.
Differential diagnoses
- Atopic dermatitis (atopic eczema)
- Urticaria
- Miliaria Pustulosa
- Miliaria Crystallina
- Miliaria Profunda
- Allergic contact dermatitis
- Hot tub folliculitis (Pseudomonas folliculitis)
Practise Miliaria rubra (heat rash) in the app
Flashcards with spaced repetition, exam questions and spot-the-diagnosis on this topic – in DermaFuchs, free of charge.
In the DermaFuchs app: 2 flashcards · 4 clinical images
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Note: This page is intended for medical education and does not replace diagnosis or treatment decisions in individual cases. Treatment and follow-up content is available in the app.