History Taking is Vital for the Diagnosis of Common Krait Snakebite.
Early in the autumn of 2009, a child in his early teens was brought to the Emergency Room of a private hospital in Mecheda (a small town in West Bengal, India) with severe convulsions. “Of course it was epilepsy” was declared by the three senior doctors. However as they were discussing the treatment, the child went into respiratory collapse within a span of 5 to 7 minutes. He was immediately shifted to the Intensive Care Unit (ICU) where he was intubated and put on a ventilator.
With dramatic change of events, the attending doctors had little time to listen to the history narrated by the child’s mother. However one of the senior doctors, a few minutes later asked the history of previous convulsions or any other history of past illness–the mother gave a peculiar but unremarkable history.
The history narrated by the mother lead to the diagnosis of Common Krait (CK) snakebite (CK is also known as Bungarus Caeruleus, Indian krait or Blue krait) .
What was the history? Well to begin with, there was not any history of a snake bite. The child was in his usual state of health till 8 AM. He had left his bed in the morning as usual and had been doing his usual chores. At about 8 AM he first complained of “pain in his throat”. The mother then took him to a village quack (A person who practices medicine without any medical license or any formal training) where he was given some medicines. But after about 40-45 minutes the boy complained of “inability to open his eyes and hazy vision”. As the mother sensed that the situation might be grave, she rushed to Mecheda, India a nearby town about 50 kms from Kolkata, India. As they were on the way, the child stopped speaking and started convulsing.
Unluckily, Indian Polyvalent Anti Snake Venom Serum (AVS) was not available in the small town. It was decided to shift the child to Kolkata. On the way in Uluberia (one Sub-divisional town), 10 vials of AVS were purchased and infused in the ambulance without any loss of time.
He was admitted in a hospital of Kolkata and was under mechanical ventilation for 5 days. This author felt obliged to be called twice to consult the patient at the hospital. Subsequently the author was also called to the Mecheda hospital to attend as a speaker in a clinical meeting to discuss about this peculiar snake bite case presentation. In the clinical meeting, about a month later the boy was present, where he still had hoarseness of voice.
None of the doctors present there had ever known that a snake can inflict painless bite. Someone in the audience questioned “How could we say so confidently that the boy was a victim of Common Krait snakebite?”
The answer was: The classical history and successful therapeutic trial.
One elderly physician of Mecheda was bold enough to confess that, in his professional life of 32 years, he had lost more than a dozen similar cases because he was not aware of such clinical presentation and hence was never able to diagnose it.
Take home points from the story above:
Though the “abdominal pain” is the commonest presentation of CK snakebites, moreover sore throat, arthralgias, calf pain, morning giddiness, are the other initial presenting symptoms of CK snakebites. All the cases ultimately progress to “acute bilateral ptosis”. Convulsion is an unusual presentation in CK snakebite. If there was a history of open floor bed in the previous night, acute bilateral ptosis is the surest sign of a CK snakebite. It should be noted that whenever there is a history of sleeping on a low height cot attached with a wall or floor bed associated with any of the above symptoms consider CK snakebite as the most important differential diagnosis even when there is no history of bite. Proper history taking (as in the proper manner you do in a medical school) is THE LIFE SAVER for hitting the diagnoses for Common Krait snakebites.