Arthropod bites and infestations

Arthropod	Comments
Bedbug	Usual reaction is limited to a punctum at the site of the bite. Pruritic red papules, often clustered, are the common allergic response. Reactions may also be maculopapular, petechial, or hemorrhagic. Anaphylaxis has been reported in sensitized persons.
Black fly (Simulium)	Itchy or painful; may vesiculate.
Chigger (Trombicula irritans, others)	Itchy maculopapular lesion.
Deer fly (Chrysops)	Painful papule with central punctum.
Flea	Early urticaria and erythema; itchy papules, often clustered.
Mosquito	Itchy papule, wheal.
Myiasis	Infestation of human tissue by fly larvae. Manifestations vary with fly species.
Pediculosis due to
Pediculus humanus (body lice)	Itchy wheals; maculopapular rash, may be hemorrhagic.
Pediculus humanus (head lice)	Itching; red papules, white nits.
Phthiriasis due to Pthirus pubis (pubic lice)	Itching; lice attach to pubic hair, eyelids.
Midge (Culicoides)	Itchy wheal and papule.
Sand fly (Phlebotomus)	Itchy or painful wheal, papule.
Scabies (Scarcoptes scabiei)	Itchy papules, vesicles; linear burrows; occasional urticaria, nodules.
Tick
Hard ticks	Regional edema; chronic nodule (tick granuloma).
Soft ticks	Macules, papules, central necrosis.
Triatomine bugs (Reduviidae)	Transient urticaria; vesicles or pruritic papules.
Tsetse fly (Glossina)	Painful, red indurated lesion.
Tungiasis (Chigoe fleas, Tunga penetrans)	Burrow into host tissue, often feet; itchy white papules or vesicles with central black depression; may ulcerate.

Graphic 69989 Version 4.0