a) CASE REPORT - Localized edema, erythema, pain, numbness and ecchymosis are relatively common, and have been documented in a number of case reports Boiruna maculata, Philodryas olfersii, P. patagoniensis and Thamnodynastes pallidus (dosSantos-Costa et al, 2000; deAraujo & dosSantos, 1997; dosSantos-Costa et al, 2000; Diaz et al, 2004; de Araujo & dos Santos, 1997; Silveira & Nishioka, 1992; Nishioka & Silveira, 1994; Gomez et al, 1994; Hayes & Hayes, 1985)
b) INCIDENCE - A review of 43 Brazilian patients who had suffered bites from the colubrid snake Philodryas olfersii ("Green Snake"), found that the most common clinical finding was local pain (37.2%), swelling (34.9%), erythema (18.6%), and ecchymosis (9.3%) (Ribeiro et al, 1999).
c) DURATION - Swelling may last one to two weeks (de Araujo & dos Santos, 1997).
d) CASE REPORTS/ADULTS
1) A 29-year-old field guide was bitten by a Thamnodynastes pallidus in the wild, with the snake remaining attached for 40 seconds. He developed edema and pain radiating to the entire extremity, along with ecchymotic lesions, and tactile warmth of the bitten finger. The edema reached its maximum extension 35 minutes following the bite. He also developed excessive salivation with a metallic taste, and a severe headache, but remained hemodynamically stable. Treatment included local application of ice, hydrocortisone and acetaminophen. The edema resolved within 36 hours (Diaz et al, 2004a).
2) Two technicians working with Philodryuas olfersii were bitten in the course of their work. The snakes were attached for 15 seconds and 2 minutes, respectively. Both patients developed progressive edema, and in the first case subcutaneous ecchymosis. Vital signs and systemic coagulation tests remained normal. The edema progressed for up to 72 hours, reaching the axilla from a finger bite in the patient with the prolonged attachment. After the initial period, the edema was accompanied by pain and restricted movement. Both patients had resolution of edema over a two-week period without permanent sequelae (de Araujo & dos Santos, 1997).
3) An 18-year-old male was bitten on the interphalangeal joint of the thumb by a Stenrrhina feminvillei, which attached for 45 seconds before being forcibly removed. Immediate pain developed and swelling occurred within 20 minutes. Edema spread to the wrist and first three fingers and resolved over a three-day period, with residual soreness lasting approximately a month (Cook, 1984).
4) A man was bitten by a large "Eastern Garter Snake" (Thamnophis sirtalis sirtalis), at the base of the right index finger. Swelling of the hand developed immediately, and increased over the next 3 hours. The next morning the hand was cold and bluish in color. Lymphadenitis occurred involving the axillary and supratrochlear nodes (Hayes & Hayes, 1985a).
e) CASE REPORTS/PEDIATRIC
1) A 16-year-old boy was bitten by a Wandering Garter snake (Thamnophis elegans vagrans) and experienced pain and swelling of the bitten finger within 5 minutes. Edema progressed to the dorsum of the hand and wrist after 6 hours. Within 24 hours, ecchymotic areas and hemorrhagic vesicles were present locally. All laboratory values remained with normal limits. Treatment consisted of local wound care, tetanus toxoid, and prophylactic antibiotics. Full recovery occurred by day 7 (Gomez et al, 1994).
2) An 8-year-old boy, was bitten on the thumb by a large "Wandering Garter Snake" (Thamnophis elegans vagrans). Within 5 minutes, swelling around the puncture wounds began. Three hours post bite, the hand was edematous and swollen to the wrist, and ecchymosis of the tissues was noted. Four hours post bite, the victim reported "soreness" of the hand, the arm became hypersensitive to movement, and flexing of the fingers proved very painful. Recovery was uneventful, and symptoms had completely resolved by the seventh day post bite (Vest, 1981).
3) A 13-year-old boy was bitten at the base of the index finger by an eastern garter snake (Thamnophis s. sirtalis) with prolonged attachment, and developed coolness, edema, and ecchymosis of the bitten hand over the next 3 hours. Lymphadenitis and tender/swollen axillary nodes also occurred. There were no systemic symptoms, all laboratory tests were normal and recovery followed within 24 hours. Subsequent bites to this subject, suggested that this was an envenomation, rather than an allergic response (Hayes & Hayes, 1985)
4) A 16-month-old girl was bitten on the left ankle while sleeping in her cradle at night. The snake was positively identified as a young male Boiruna maculata. Shortly after the bite, a tourniquet was placed above the knee, and was removed on arrival at the hospital. Fang marks were seen at the ankle, as well as edema, local erythema and cyanosis. Clotting time was normal. The patient was discharged without treatment. Seven hours later, she was readmitted with pronounced edema and pain, ecchymotic lesions, enlarged inguinal lymph nodes, cyanosis of the ankle and foot and warmth of the bitten limb. Vital signs, clotting time, and urinalysis were within normal limits. No systemic effects were observed. The patient was given 200 mL of Bothrops antivenom IV (Instituto Butantan), along with analgesics, elevation, and hydration. By the third day, the pain and cyanosis started decreasing. On the fifth day, the edema and ecchymosis were decreased. The patient was discharged on day 6 with only mild ankle edema and ecchymotic lesions (dosSantos-Costa et al, 2000).
5) A 5-year-old boy was bitten by the Colubrid snake Philodryas patagoniensis, and developed swelling and warmth in the affected limb (Nishioka & Silveira, 1994).