Spider bites
Brown Recluse
Clinical Features
- Bite is initially painless
- Mild reaction
- Most common
- Mild erythematous lesion that later becomes firm and heals without scar
- Severe reaction
- Begins w/ mild-severe pain several hrs after bite accompanied by erythema and swelling
- Hemorrhagic blister then forms surrounded by vasoconstriction-induced blanched skin
- By day 3 or 4 hemorrhagic area may become ecchymotic
- Leads to "red, white, and blue" sign (erythema, blanching, ecchymosis)
- By end of first week ecchymotic area may become necrotic w/ eschar formation
- Systemic effects
- Rare
- Occur predominantly in children 24-72hr after the bite
- Include nausea/vomiting, fever, arthralgias, thrombocytopenia, rhabdo, renal failure
Treatment
- Local wound care
- Abx are indicated only if signs of infection exist; secondary infections are uncommon
Black Widow
Clinical Features
- Local
- Pinprick sensation; then increasing local pain that may spread to entire extremity
- Erythema appears 20-60 min after the bite
- Pain begins to abate after several hours and disappears by 2-3d
- Systemic
- Muscle cramp-like spasms in large muscle groups (although exam rarely reveals rigidity)
- Pain becomes generalized
- Severe abdominal wall musculature pain and cramping is well described
- Headache, nausea/vomiting, diaphoresis, photophobia, dyspnea
- A-fib, myocarditis, priapism, and death are rare
Treatment
- Pain and muscle spasms
- Opiods and benzos
- Systemic illness
- Antivenom
- Consider for:
- Children
- Pregnant women
- Elderly
- Consider for:
- Antivenom
Disposition
- Consider admission for:
- Symptoms of moderate envenomation
- Pregnant women
- Children
- Pts w/ preexisting cardiovascular disease or HTN
Tarantulas
Clinical Features
- Abdominal hairs may be flicked a short distance when threatened
- Rarely penetrate human skin but can imbed deeply into conjunctiva and cornea
- Bites can be painful but systemic symptoms other than fever are unusual
Management
- Red eye and pain after handling a tarantula necessitates an ocular exam
- Hairs may be difficult to detect on slit lamp
- Treatment is surgical removal of hairs and topical steroids
See Also
Source
- Tintinalli
- Rosen's