Select Spiders

Black with round abdomen; red hourglass-shaped marking on ventral surface

Toxin: α-latrotoxin (depolarizes neuron)

Acute edema and pain at site of bite, systemic symptoms resembling acute surgical abdomen

Treatment: antivenin, benzodiazepine, IV calcium gluconate

Light brown with small body and long, delicate legs

Toxin: sphingomyelinase D (phospholipase)

Erythema at site of bite → bulla → necrosis; systemic symptoms associated with disseminated intravascular coagulation

Treatment: ice, elevation, ± dapsone

Hobo spider
Funnel web spider

Tan to brown hairy spider with herringbone striped patten on abdomen

Toxin: causes local mecrosis and affects CNS

Painless bite, but can lead to necrotic eschar, ± visual changes, weakness, malaise

Treatment: supportive

Hogna spp.

Brown to gray spider with peach-colored stripe down cephalothorax; eyes arranged in 3 rows, bottom row with four small eyes

Toxin: histamine

Painful bites → ± lymphangitis or eschar

Treatment: supportive

Bright green with red spots, black spines on legs

Painful bite with tenderness, pruritus
(usually no necrosis)

Treatment: supportive

Cheiracanthium spp.

Beige or pale yellow, no distinguishing markings

Toxin: lipase

Painful bite

Treatment: supportive

Phidippus spp.

Dark body hairs, variable white pattern, unique eye arrangement with largest two eyes in middle front row

Toxin: hyaluronidase

Painful bite

Treatment: supportive

Theraphosidae spp.

Large hairy spiders

Toxin: urticating hairs thrown at skin and eyes – penetrate epidermis

Pruritus with wheal and flare reaction at site of hair penetration; ophthalmia nodosa
(ocular inflammation with exposure to hairs, can lead to vision loss)

Treatment: supportive