Anti-snake venom sera contain immune
globulins or their fragments purified from plasma after the donor animals have been immunized with snake venom, and are mainly used for the treatment of
envenomation.
1 The
immunoglobulins in
antivenom bind to the free toxins in the snake venom to neutralize the toxicity.
2 However, there are some adverse reactions in the use of antivenom, such as immediate
hypersensitivity (8%) and serum sickness (13%).
3 It is a very rare condition that the patient was treated with the same antivenom. In this report, we present a case of envenomation treatment for an old male patient who did not have hypersensitivity in the first treatment, but developed immediate hypersensitive reaction during the second treatment with the same dose of serum after re-bitten by the same snake. We report the clinical manifestations, treatments, possible
pathogenesis and preventative strategies.
Case report
Diagnosis and treatment
First visit
The patient, male, 75 years old, had no previous history of
drug allergy, asthma or
allergic rhinitis. In the morning of September 26, 2015, the patient was bitten at the back of the right hand by a venomous snake in the kitchen (adder, a common snake in his area). The patients felt local pain and swelling that extended to the right forearm. No obvious wound bleeding, disturbance of consciousness, dizziness, nausea, vomiting, chest tightness nor
dyspnea was found. He visited the hospital 1 h after the bite and received full examination.
The temperature was 36.5 °C, pulse 80 beats/min, respiratory rate 21 times/min, and blood pressure 116/88 mmHg. There was swelling from the back of the right hand to the right forearm. Two teeth marks were seeded at the wound site. Opisthenar was blue and purple in color with swelling; the fingers were inflexible. Blood routine tests showed that
white blood cell count (WBC) was 11.2 × 109/L, the
neutrophil ratio rised to 87% and others were normal.
The patient was immediately given anti-adder venom (National Drug Approval No. S1082108, production lot number No. 20150501, Sailun Biological Technology, Shanghai, China) after skin
allergy test showed negative result. The serum was intravenously infused with the dose of 6000 U and the patient showed no signs of allergy or other discomfort. The wound was debrided and topically applied with the powder of
Jidesheng snake pill. Meanwhile, oral administration of the pill (8 g) and
intramuscular injection of 15,000 U of refined
tetanus antitoxin and 40 mg of methylprednisolone were done for anti-inflammation. Moreover intravenous drip of propacetamol (1 g) for pain relief and
ceftazidime (2 g) for anti-infection was conducted. After one day of treatment, the swelling was subtotal subsided and opisthenar and fingers were flexible. The patient had no other discomfort and was discharged.
Second visit
On October 25, 2015, the patient was bitten again at the same site (the thumb and
index finger of right hand) around 7:00. The snake was believed to be the same. The patient was severely painful with a small amount of bleeding in the wound. The patient had no dizziness,
vertigo,
numbness,
heart palpitation, chest tightness, shortness of breath, nausea, vomiting, or abdominal pain. After treatment of the wound with ethanol by himself, the pain was not relieved. Thirty min later, the wound exacerbated with subcutaneous blisters appeared. The pain spread to opisthenar and extended to the
upper limb. Opisthenar and the wrist were swollen, which did not subside after herbs application.
At 12 p.m., the patient visited the hospital. Physical examination showed that the temperature was 36.7 °C, pulse 82 beats/min, breathing 21 times/min and blood pressure 118/84 mmHg. The patient was conscious with smooth breathing and normal rhythm. The teeth marks of the snake were visible at the right thumb and index finger with local and dark-red swelling. There were some blisters and the swelling had extended to the upper arm from opisthenar. The circumferences 10 cm above the rasceta and olecranon were 23.5 cm and 30 cm, respectively. The same level of the sound limb was 21 cm and 26 cm, respectively. Opisthenar was heavily swollen with touch pain and normal skin temperature and slightly high tension. The five fingers were flexed with poor flexibility but normal feeling. Laboratory tests showed that WBC was 15.6 × 109/L, the neutrophil ratio 92.5%.
The patient was immediately given local
debridement and rinsed with hydrogen
peroxide, wound washing, oral administration of
Jidesheng snake pill (8 g) and other anti-inflammation & anti-infection treatment as the first visit. Skin allergy test for
antivenom was preformed again but the result was positive with
erythema papula of 2.2 cm in diameter. Upon obtaining the informed consent, the patient was desensitized and infused slowly (1 mL/min) with 6000 U serum in 500 mL saline according to the protocols approved by the CFDA (China Food and Drug Administration). The patient was transferred to the emergency room to receive
desensitization treatment for 15 min along with ECG and
oxygen saturation monitoring. He then felt hot at both feet but no other discomforts. 5 min later, he complained of dizziness, malaise, itching of chest and back, chills and cold extremities. Examinations showed that the respiratory rate was 22 times/min, pulse 98 beats/min, and blood pressure dropped to 98/49 mmHg. He had pale face with large area of erythema, rashes on the chest and swellings on the back. These symptoms were considered as allergic reactions and the infusion was stopped immediately. He was given oxygen, the oxygen concentration was 5 L per minute. He was also given intramuscular injection of
Promethazine (1mL) and intravenous injection of methylprednisolone (40 mg) and intravenous drip of 100 mL 10%
glucose with 10 mL 10% calcium gluconate. Five min later, the patient achieved relief from the symptoms and his complexion restored gradually with no more chills.
The temperature was measured to be 36.7 °C, breathing 21 times/min, heart beating 88 times/minute, blood pressure 121/88 mmHg and blood oxygen saturation 99%. One hour later, the rashes on the back and chest gradually faded and disappeared 6 hour later without other discomforts. He was later treated for swelling, pain, anti-infection as well as oral administration and topical application of snake pills. After 5 days of treatment, the pains and swelling were obviously relieved. Examinations showed that WBC was 9.93 × 109/L, neutrophil ratio of 69.5%. The patient was uneventfully discharged