Bedbug bites
- Pruritic, urticarial papules most frequently on exposed areas
- Often linear configuration of 3-4 lesions (“breakfast, lunch, and dinner”. Ew.)
- Tx: corticosteroids + antihistamines
Flea bites
- Usually flat, firm urticarial papules surrounded by red halos, sometimes bleed. Typically around ankles, lower leg
- Also often linear or clustered pattern
- Tx: corticosteroids + antihistamines
Scabies
- Burrow is classic (fine, serpiginous line with terminal black speck (mite)), most commonly on intertriginous spaces, classically spares head/neck
- Pruritus more intense at night when patient is warm
- Tx: permethrin (second line is lindane) + antihistamines
Spider bite
- Necrotic/dusky center within red, inflammatory plaque is classic, often edema and erythema
- Most suspected spider bites in the US turn out to be the result of other causes, such as cellulitis or furunculosis. Be cautious about narrowing your differential.
- Wound care + tetanus, antivenom as indicated