Bed Bugs
Basics
- Nocturnal, wingless blood parasites, 5-7 mm oval, reddish-brown
- Cimex lectularius (temperate urban), Cimex hemipterus (tropical)
- Reside in crevices of mattresses, box springs, headboards, baseboards
- Bites provoke immune reactions: from minimal to pruritic maculopapular rash, urticarial, or anaphylactoid responses
- Do not transmit known pathogens
Epidemiology
- Increasing incidence and treatment difficulty due to travel, pesticide changes, secondhand furniture
- Infestation prevalence rising 10-30% in US public spaces (schools, hospitals, hotels)
- Over 75 Cimicidae species; only 3 bite humans (lectularius, hemipterus, Leptocimex boueti)
Etiology and Pathophysiology
- Attraction to body warmth and CO2
- Host immune responses to salivary proteins mediate symptoms: IgG for urticaria, IgE for bullous reactions
- Bites cause skin reactions via immunologic hypersensitivity
Risk Factors
- Immunocompromise
- Frequent travel and high hotel turnover
- Use of secondhand furniture
Prevention
- Vacuum regularly, reduce clutter, seal cracks
- Launder bedding/clothing >130°F (50°C) for 2 hours or freeze at ≤20°F (-5°C) for ≥5 days
- Professional extermination services often needed; canine detection available
- Traps using CO2 and heat effective but costly
Diagnosis
History
- Recent travel, possible bed bug sightings, blood specks on sheets
- New pruritic lesions on exposed skin areas on awakening
Physical Exam
- Erythematous, pruritic papules in irregular linear patterns
- Lesions mostly on face, neck, arms, legs, shoulders
- May present as papular urticaria, bullous lesions, or anaphylaxis
Differential Diagnosis
- Urticaria, insect/spider bites
- Scabies
- Dermatitis herpetiformis
Diagnostic Tests
- Skin scraping with mineral oil (negative helps exclude scabies)
- Skin biopsy: nonspecific perivascular eosinophilic infiltrate consistent with arthropod bite
Treatment
General Measures
- Address skin symptoms, eradicate infestation, and behavioral health impact
- Self-limited; lesions resolve in 1-2 weeks
Medication
- Oral antihistamines (diphenhydramine, hydroxyzine)
- Topical antipruritics (pramoxine, calamine, doxepin cream)
- Low-to-mid potency topical corticosteroids for up to 2 weeks
- Systemic corticosteroids in severe cases
- Treat secondary infections with antibiotics targeting Staph/Strep (cephalexin, doxycycline, clindamycin, mupirocin)
- Epinephrine for anaphylaxis
Additional Therapies
- CDC recommends integrated pest management: clutter removal, sealing cracks, heat treatment, vacuuming, nonchemical pesticides
- Emerging methods include xenointoxication (oral arthropodicidal agents)
Ongoing Care
Follow-up
- Usually not needed unless severe or anaphylactoid reactions
- Behavioral health support as needed
Patient Monitoring
- Inspect hotel rooms (mattresses, luggage racks) before use
- Reduce clutter, keep luggage off beds
Patient Education
- Avoid scratching to reduce superinfection risk
- Regularly inspect bedding, furniture, and luggage
- Refer to CDC and EPA resources for detailed pest control guidance
Complications
- Bed bug dermatitis and allergic reactions
- Asthma exacerbations, anaphylaxis (rare)
- Psychological distress: insomnia, anxiety, depression, delusional parasitosis
- Secondary bacterial infections
- Rare transmission of blood-borne diseases
Clinical Pearls
- 90% infestations occur within 3 feet of the bed
- Bed bugs resistant to many OTC pesticides (permethrin, cyfluthrin, bifenthrin)
- Heat treatment effective for eradication, tropical species require higher temperatures