All Emergencies - Basic life support principles:

  1. Maintain an airway
  2. Assess breathing
  3. Monitor circulation
Monitor and record all vital signs.
Allergic Reaction

Allergic skin reaction:

  1. Position patient comfortably. Monitor patient's breathing and circulation closely, since the reaction can progress quickly.
  2. Assess speech:
    1. During a mild reaction, patient speaks without difficulty.
    2. Wheezing and labored breathing indicate the reaction is progressing, requiring EMS assistance.
    3. A high pitched crowing sound indicates soft tissue edema at the larynx. This is life-threatening - activate EMS stat - See # II thru V below.
  3. If speech remains normal, but skin is flushed and hives appear, an antihistamine must be administered to control the reaction. (See Roman Numeral I below.)
    • Parental administration (IM or IV) should prevent involvement of respiratory or cardiovascular symptoms.
  4. If reaction involves skin only, no need to call EMS. Patient may be dismissed from the office after about an hour if the symptoms do not progress or recur.


I. Delayed onset (>60 minutes) - allergic skin reaction:

Oral antihistamines - for 3 days:

  • Diphenhydramine (Benadryl) 50mg qid adults, 25mg qid children or
  • Chlorpheniramine 2-4mg tid-qid adults, 2mg q4-6h children

Details: Diphenhydramine (50mg) or chlorpheniramine (10mg) IV or IM into the mid-deltoid or vastus lateralis muscles.

IM injected antihistamines will reduce the itching in 10-30 minutes, IV injections in 2-4 minutes. Skin rash or hives will remain, but itching will subside. Whenever parenteral antihistamines are administered, a 3-day regimen of oral antihistamine should be prescribed.


II. Rapid onset allergic skin reaction (= systemic), but NO CVS or respiratory involvement:

  1. The more rapid the onset of signs & symptoms, the more dangerous & life threatening.
  2. Administer parenteral antihistamine (IV preferred - has onset within minutes; IM takes 10-30 minutes)
  3. Do not permit patient to leave until signs & symptoms have resolved.
  4. Do not permit patient receiving parenteral antihistamine to drive automobile.
  5. ***Always prescribe oral antihistamine for 3 days following parenteral use.
  6. Consult M.D. prior to next appointment.


III. Rapid onset w/cardio-vascular (CVS) or respiratory involvement:

  1. Activate EMS stat. Monitor & record b.p., heart rate/rhythm & respiratory rate.
  2. Administer Epinephrine IM (not sub-Q - it takes too long) - 0.3mg q5 minutes, until recovery (i.e. resolution of CVS/respiratory signs & symptoms)
  3. Administer antihistamine IM upon recovery to prevent relapse


IV. Respiratory allergic reaction:

  1. Summon EMS
  2. Administer bronchodilator spray (Albuterol = Proventil or Ventolin)
  3. Administer epinephrine 0.3mg IM q5m.
  4. Administer antihistamine parenterally.


V. Anaphylaxis - click here.