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Miliaria crystallina in Adult
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Miliaria crystallina in Adult

Contributors: David O'Connell MD, Susan Burgin MD
Other Resources UpToDate PubMed


Miliaria is caused by occlusion of the epidermal portion of eccrine sweat ducts. There are 3 commonly recognized forms of miliaria that vary in symptoms, clinical presentation, and time course depending upon the level of occlusion: miliaria crystallina, miliaria rubra (prickly heat), and miliaria profunda (skin-colored papules with possible associated hypohidrosis or anhidrosis). Miliaria pustulosa is a pustular variant that may be seen in chronic cases of miliaria rubra.

Miliaria crystallina, also referred to as sudamina, is due to occlusion of the eccrine ducts at the superficial epidermis or stratum corneum. It may occur at any age but is common in neonates and infants, probably secondary to the immaturity and weakness of the duct structure. Clinically, it presents as largely asymptomatic 1- to 2-mm fragile vesicles. It has predilection for the face, neck, upper torso, and occluded areas. Fever, exposure to warm and humid environmental conditions, and occlusion (excessive clothing or swaddling) are predisposing factors.

Superficial occlusion is thought to result from increased hydration compounded with humidity and sweating. When the occlusion of the sweat duct is deeper in the epidermis, miliaria rubra (prickly heat), miliaria pustulosa, or miliaria profunda (skin-colored papules with possible associated hypohidrosis or anhidrosis) may result.


L74.1 – Miliaria crystallina

44279002 – Miliaria crystallina

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Diagnostic Pearls

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Differential Diagnosis & Pitfalls

  • Miliaria rubra and Miliaria profunda – These miliaria variants are not vesicular and present as papules and/or pustules.
  • Varicella – Presents with vesicles on an erythematous base (eg, "dewdrops on a rose petal") and with lesions in different stages.
  • Incontinentia pigmenti – Stage 1 (vesicular); swirled and linear Blaschkoid pattern.
  • Scabies – Vesicles and burrows. Examine caregivers.
  • Bullous impetigo – More bulbous but also fragile, leading to erosions.
  • Folliculitis – Has follicularly based pustules.
  • Herpes simplex virus – Presents with painful crops of vesicles that often occur near a mucosal surface.
  • Acute generalized exanthematous pustulosis (AGEP) – Pustules are opaque, not clear as in miliaria.
  • Lesions may resemble Toxic epidermal necrolysis with the presence of desquamation. However, miliaria crystallina does not have the intense erythema, mucosal involvement, or systemic illness associated with toxic epidermal necrolysis.
  • Bullous drug eruption

Best Tests

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Management Pearls

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Drug Reaction Data

Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.

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Last Reviewed:07/11/2019
Last Updated:07/14/2019
Copyright © 2024 VisualDx®. All rights reserved.
Miliaria crystallina in Adult
A medical illustration showing key findings of Miliaria crystallina : Fever, Hot and humid environment exposure, Primarily truncal distribution, Tiny vesicles
Clinical image of Miliaria crystallina - imageId=2346509. Click to open in gallery.  caption: 'A close-up of myriad tiny vesicles on the chest.'
A close-up of myriad tiny vesicles on the chest.
Copyright © 2024 VisualDx®. All rights reserved.