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

bedbug

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