Miliaria

Acute inflammatory disorder of the eccrine sweat ducts caused by obstruction of sweat outflow

Epidemiology

• Common in neonates and infants

• Also affects adults in tropical climates

• Frequently seen during hot, humid weather

• Associated with occlusion, fever, and excessive sweating

Aetiology

• Heat and humidity

• Occlusive clothing or dressings

• Fever

• Prolonged bed rest

• Immature sweat ducts (infants)

Pathophysiology

• Obstruction at different levels of the eccrine sweat duct

• Sweat leaks into the epidermis or dermis

• Triggers an inflammatory response

• Level of obstruction determines the clinical type

Clinical presentation

🧩 Classification (Based on Level of Obstruction)

Miliaria Crystallina — Sudamina

• Clear, thin-walled vesicles

• No erythema or symptoms

• Common on trunk, neck

• Seen in neonates or febrile patients

Miliaria Rubra (“Prickly Heat”)

• Erythematous papules, papulovesicles

• Pruritic or stinging sensation

• Common on neck, axillae, groin

• Most common and symptomatic form

Miliaria Profunda

• Firm, flesh-colored papules

• Occurs after repeated episodes of miliaria rubra

• Associated with anhidrosis

• Rare

Investigations

• Clinical diagnosis

• No laboratory tests required

• Skin biopsy (rare): level-specific sweat duct obstruction

Management

General Measures (Mainstay)

• Cool environment

• Reduce sweating

• Loose, breathable clothing

• Avoid occlusive products

Medical Treatment