Allergic skin reaction:
- Position patient comfortably. Monitor patient's breathing and circulation closely, since the reaction can progress quickly.
- Assess speech:
- During a mild reation, patient speaks without difficulty.
- Wheezing and labored breathing indicate the reaction is progressing, requiring EMS assistance.
- A high pitched crowing sound indicates soft tissue edema at the larynx. This is life-threatening - activate EMS stat - See # II thru V below.
- 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.)
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.
- Parental administration (IM or IV) should prevent involvement of respiratory or cardiovascular symptoms.
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 middeltoid 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:
- The more rapid the onset of signs & symptoms, the more dangerous & life threatening.
- Administer parenteral antihistamine (IV preferred - has onset within minutes; IM takes 10-30 minutes)
- Do not permit patient to leave until signs & symptoms have resolved.
- Do not permit patient receiving parenteral antihistamine to drive automobile.
- ***Always prescribe oral antihistamine for 3 days following parenteral use.
- Consult M.D. prior to next appointment.
III. Rapid onset w/cardio-vascular (CVS) or respiratory involvement:
- Activate EMS stat. Monitor & record b.p., heart rate/rhythm & respiratory rate.
- Administer Epinephrine IM (not sub-Q - it takes too long) - 0.3mg q5 minutes, until recovery (i.e. resolution of CVS/respiratory signs & symptoms)
- Administer antihistamine IM upon recovery to prevent relapse
IV. Respiratory allergic reaction:
- Summon EMS
- Administer bronchodilator spray (Albuterol = Proventil or Ventolin)
- Administer epinephrine 0.3mg IM q5m.
- Administer antihistamine parenterally.
V. Anaphylaxis - click here.