RISK FACTORS: Living environment, Climate, Season, Clothing, Lack of protective measures, Perfumes, colognes, Previous sensitization, Young or elderly at more risk
APPROPRIATE HEALTH CARE
. Outpatient or inpatient, depending on individual response to injury
. Hospitalize for severe systemic reactions with threatened airway obstruction, bronchospasm, hypotension,
severe angiodermatitis or pain
GENERAL MEASURES
. First aid measures, local treatment, activate emergency services in severe reactions. If history of allergy or large envenomations, dont wait to seek emergency care.
. Use ANA kit and over-the-counter antihistamines, if available and required
. Local (depending on severity)
. Remove stinger (scrape it out - dont squeeze with tweezer)
. Cleanse wound
. Ice packs to bite or sting site (alternate 10 minutes on/10 minutes off)
. Elevation of affected part
. Rest the affected area
. Debride ulcers
. Drain abscesses
. Systemic (depending on severity, and type of reaction); home use - Epi-Pen
. Adequate airway (intubation, tracheostomy) - if needed to bypass obstruction
. Oxygen (4-6 L/min) - if needed for respiratory distress
. Hospitalize and observe 24-48 hours
SURGICAL MEASURES Optimal treatment of necrotic spider bites is not well defi ned. Surgical repair may be required of severe ulcerative lesions, but not until primary necrotizing process is complete.
ACTIVITY Rest to limit spread of poison
DIET No special diet; nothing by mouth if severe systemic reaction
PATIENT EDUCATION
. Protective measures, ANA kit use, risks
. Individuals with known sensitivity should wear medical identifi cation (bracelet, tag) or carry a card
DRUG(S) OF CHOICE
. Local (depending on severity)
. Analgesics
. Antihistamines - diphenhydramine (Benadryl) 25-50 mg qid
. Steroids topical or oral - prednisone 20-40 mg/day
. Antibiotics
. Systemic (depending on severity and reaction type)
. Epinephrine [1:1000] subcutaneous: to combat urticaria, wheezing, angioedema - child 0.01 mL/kg,
adult 0.3-0.5 mL
. Diphenhydramine: 25-50 mg IV or IM, to combat urticaria, wheezing, angioedema
. IV fluids (Ringers lactate): if needed for hypotension, hypovolemia
. Dopamine: 200 mg in 250 mL at 5 mcg/kg/min - to correct vascular collapse. Titrate to maintain systemic
blood pressure over 90 mm Hg.
. Hydrocortisone: 100-250 mg IV, if needed for severe urticaria or spider bite
. Tetanus prophylaxis and antibiotics: if indicated
. Diazepam (Valium): 5-10 mg, if needed for severe muscle spasms
. Morphine or meperidine (Demerol): if needed for pain
. Antivenins (e.g., Black Widow spider, scorpion) are available and appropriate in certain cases based on
availability and identifi cation of organism
. Topical insecticides
. Lice: 1% permethrin (Nix, Elimite) is drug of choice, but 0.5% malathion (Ovide) or pyrethrin (Rid) are
effective. Lindane (Kwell) has fallen out of favor for the treatment of lice due to growing resistance and
reported cases of neurotoxicity.
. Scabies: 5% permethrin is drug of choice, but 10% crotamiton (Eurax) or lindane are effective
ALTERNATIVE DRUGS
β’ Other antihistamines, e.g., loratadine (Claritin), fexofenadine (Allegra), etc.
β’ Oral ivermectin (Mectizan) appears effective for lice and scabies, but is not FDA approved for this purpose.
It is administered in a dose of 200 micrograms/kilogram once, followed by a second dose of equal size 1-2
weeks later.
PATIENT MONITORING Followup wound care
PREVENTION/AVOIDANCE
. Avoid re-exposure in known hypersensitive individuals
. Prescribe anaphylactic (ANA kit) or Epi-Pen, if indicated
. Educate on risks of increasing anamnestic responses in future
. Consider desensitization with immunotherapy in severe cases
. DEET or other proven insect repellants
. Permethrin applied to clothes is better against ticks than DEET
POSSIBLE COMPLICATIONS
. Infection
. Bacterial
. Arthropod associated diseases with tick, fly, bug and mosquito bites, e.g., lyme borreliosis, rickettsial
disease (Rocky Mountain spotted fever), arboviral encephalitis, malaria, leishmaniasis, trypanosomiasis,
dengue
. Scarring
. Drug reactions
. Multisystem failure
. Death
EXPECTED COURSE/PROGNOSIS
. Minor reactions - excellent
. Severe reactions - excellent with early, appropriate treatment