Environmental heat diagnoses

Heat Edema

1. Self-limited, mild edema of feet, ankles, and hands
2. Appears w/in first few days of exposure to a hot environment
   1. Commonly seen in travelers just arriving from a colder climate
3. Resolves spontaneously in days to weeks
4. Treatment
   1. Elevation of legs
   2. Use of support hose
   3. Diuretics are contraindicated

Miliaria (Heat Rash)

1. Pruritic, maculopapular, erythematous rash over normally clothed areas of body
   1. See Media:Miliaria.jpg
2. Pathophysiology
   1. Acute inflammation of sweat ducts caused by blockage of pores by macerated skin
      1. Ducts become dilated under pressure and ultimately rupture
         1. This produces superficial vesicles in malpighian layer of skin on a red base
            1. May progress to miliaria profunda (white papules) if duct ruptures a second time
3. Treatment
   1. Antihistamines
   2. Dicloxacillin or erythromycin if appears superinfected

Heat Cramps

1. Painful, involuntary, spasmodic contractions of skeletal muscles
   1. Usually affects calves, thighs and shoulders
2. Occurs to pts who are sweating profusely and replace fluid losses with water
   1. May occur during exercise or during a rest period several hrs later
3. Treatment
   1. Self-limited
   2. Pain is difficult to tx; often does not respond to opiates alone
   3. Gatorade or NS IV

Heat Tetany

1. Hyperventilation > respiratory alk > extremity/circumoral paresthesia, carpopedal spasm
2. Differentiate from heat cramps based on little pain, no cramping in muscle compartments
3. Treatment
   1. Remove from heat, decrease resp rate

Heat Syncope

1. Variant of postural hypotension
   1. Results from combination of volume depletion and peripheral vasodilatation
   2. Occurs in nonacclimatized during early stages of heat exposure (esp elderly)
2. Management
   1. Diagnosis of exclusion
   2. Remove pt from heat source, give PO or IV rehydration
   3. Hospitalization usually is not necessary

Source

Tintinalli