Studies

A. contortrix

Rodgers et al. 1992: 32 A. contortrix bites in children; identification: criteria not specified.

White et al. 1988: 26 A. contortrix bites; identification: criteria not specified; no signs of envenoming 4/26, local signs of envenoming 22/26.

A. piscivorus

No studies or case reports available with reliable identification of the species that caused of the bite. A. piscivorus bites are believed to be somewhat more dangerous than A. contortrix bites, but this has not been confirmed in a study.

Signs & symptoms

Autopharmacological effects

A. contortrix

Nausea, vomiting 1/26 (White et al. 1988). Vomiting 2/32 (Rodgers et al. 1992).

Local effects

A. contortrix

Local pain 5/26, local erythema 3/26, local ecchymosis 12/26, local oedema 18/26, regional swelling 1/26, tender regional lymph nodes 1/26 (White et al. 1988).
Local swelling and ecchymosis 32/32 (Rodgers et al. 1992).

Morbidity

A. contortrix

No significant long-term effects 32/32 (Rodgers et al. 1992).

Case fatality rate

A. contortrix
0/32 (Rodgers et al. 1992).
0/26 (White et al. 1988).

Laboratory and physical investigations

1. Haemostasis
Type of haemostatic defect
A. contortrix, A. piscivorus

The coagulation-promoting components of the A. contortrix venom generally appear not to cause any clinically relevant haemostatic defects.

For a description of the coagulation-promoting components, see Stocker 1990.

Haemostatic parameters

A. contortrix

Treatment (specific)

Antivenom

Wyeth antivenom (Crotalidae), Philadelphia, USA.

Antivenom indications
A. contortrix

2/26 patients received antivenom (White et al. 1988). Administration of antivenom was most probably unnecessary also in these patients.

3/32 patients received antivenom (Rodgers et al. 1992). Administration of antivenom was most probably unnecessary also in these patients.

Generally, administration of antivenom not necessary (Rodgers et al. 1992; White et al. 1988).