Arthropod bite or sting in Adult
Reactions may be more pronounced in the immunocompromised patient. An exaggerated, sometimes bullous reaction to an arthropod bite is characteristic of certain immunosuppressed states, especially a hematopoietic malignancy or HIV disease. In HIV-infected individuals, arthropod assaults may result in an extremely pruritic skin eruption called "pruritic papular eruption."
Arthropods include insects (stinging or venomous hymenoptera [eg, bees, wasps, fire ants] and non-venomous insects [eg, mosquitos, chiggers, fleas]) as well as ticks, mites, spiders, scabies, and body lice. Other arthropods often remain unidentified.
Arthropods may transmit human illness (including tick bite fever, Lyme disease, Rocky Mountain spotted fever, a variety of encephalitides, malaria). Venomous bites may trigger systemic toxic or allergic reactions, including anaphylaxis. An ascending paralysis caused by a neurotoxin may occur after a tick bite.
Some arthropod infestations, such as pediculosis capitis, scabies and crusted scabies, are highly contagious and pose a particular problem in the institutional setting.
There are highly variable global distributions of insects and arthropods. In returning travelers, insect bites are the fourth most common skin complaint diagnosed.
T63.481A – Toxic effect of venom of other arthropod, accidental (unintentional), first encounter
409985002 – Arthropod bite wound
Differential Diagnosis & Pitfalls
- Scabies should be identified by microscopic examination of skin scrapings.
- Flea bites, in particular, can cause vesicles and bullae, which may mimic bullous pemphigoid, bullous impetigo, and linear IgA disease.
- In contrast to cellulitis, bites and stings are often multifocal and may be bilateral. There may be a visible punctum, and the patient may have a recollection of insect exposure. There may be concomitant cellulitis, however, as bites and stings often serve as an important nidus of infection.
- Acne excoriée
- Pityriasis lichenoides et varioliformis acuta
- Lymphomatoid papulosis
- Erythema nodosum
- Zoster or other herpes virus infection
- Fixed drug eruption
- Tinea corporis
- Contact dermatitis (allergic, irritant)
- Eosinophilic dermatosis of hematologic malignancy