Question

J.E., a 37-year-old woman with no prior history of allergies, was working in her yard when she received a sting on the right wrist from a yellow-jacked wasp. Several minutes later she complained of a itching sensation and cramping abdominal pains. She then became acutely short of breath with wheezing. A patchy erythema radiating from the area of the sting was noted along with swollen eyelids and lips. A neighbor took her to the hospital where she became very faint and could not talk or provide information to assist with a diagnosis. Vital signs were as follows: BP of 60/34; Pulse of 156; Respiration rate of 40

Epinephrine 1/1000 was administered IM along with 100 mg of hydrocortisone. Within minutes, an improvement in the respiratory rate was noted and blood pressure increased to 100/70 with a pulse of 112.

QUESTION:

2) Explain the rationale for each of the following signs and symptoms:

- Increased pulse

- erythema

- low Blood Pressure

Answer 1

Sting of the wasp would lead to allergic responses, as the wasp would have injected its venom . Now the venom is the antigen to her body, so her body produce antibodies . The interaction between an antigen and an antibody results in an allergic reaction. Abnormal response to any stimulus is termed hypersensitivity ,which is a severe form of allergic reaction. Severe form of allergy is called anaphylaxis .This is a life threatening condition characterized by hypotension, erythema, tachycardia , bronchospasm, layngeal edema, cyanosis , vomiting, diarrhea , seizures even coma & death.

Immunoglobulins of IgE is involved in allergic responses. Two or more IgE molecules bind to the allergen and trigger the mast cells to produce more chemicals like histamine, serotonin, neutrophil factors which are responsible for the signs and symptoms like tachycardia, erythema and hypotension.

Increased pulse : Tachycardia is abnormal increase in heart rate. This may be a result of hypotension or the allergic reaction may have triggered the histamine response on the heart increasing its rate of contraction and relaxation.

Erythema: As there is tissue injury due to wasp sting , there is diffuse redness noted in skin due to allergic responses .

Low blood pressure: The histamine released by her body during due to the wasp venom has caused the blood vessels to widen which leads to a sudden and severe drop in blood pressure.