Miliaria

Background

• Also known as heat rash, lichen tropicus, miliaria rubra, prickly heat

Pathophysiology

• Acute inflammation of sweat ducts caused by blockage of pores by macerated skin
• Ducts become dilated under pressure and ultimately rupture
• Often seen in areas of friction
• This produces superficial vesicles in malpighian layer of skin on a red base
• May progress to miliaria profunda (white papules) if duct ruptures a second time

Clinical Features

Miliaria

• Pruritic, maculopapular, erythematous rash over normally clothed areas of body

Differential Diagnosis

Environmental heat diagnoses

• Heat cramps
• Heat edema
• Heat exhaustion
• Heat tetany
• Heat stroke
• Heat syncope
• Miliaria
• Hyperthermia

Maculopapular rashes

• Infectious
  • Adenovirus
  • Arbovirus
  • Chikungunya
  • EBV
  • Ehrlichiosis
  • Enterovirus
  • Fifths disease
  • HSV 6
  • Leptospirosis
  • Lyme
  • Measles
  • Meningococcemia
  • Mycoplasma
  • Parvovirus (B19)
  • Primary HIV
  • Psittacosis
  • Rickettsia
  • Rubella
  • Rubeola
  • Scabies
  • Secondary syphilis
  • Streptobacillus moniliformis
  • Typhoid fever/typhus

• Noninfectious
  • Acrodermatitis enteropathica
  • Allergy
  • Dermatomyositis
  • Erythema marginatum
  • Erythema multiforme
  • Lupus
  • Miliaria (Heat Rash))
  • Serum sickness
  • Sweet's syndrome

Evaluation

• Clinical diagnosis

Management

1. Antihistamines
2. Dicloxacillin or erythromycin, if appears superinfected

Disposition

• Outpatient

See Also

• Heat Emergencies