Which factor precipitates painful episodes in sickle cell anemia?

Which factor precipitates painful episodes in sickle cell anemia?

• A. Dehydration
• B. Increased iron intake
• C. High white blood cell count
• D. Low platelet count

Answer: (A)

In sickle cell disease, painful episodes come from vaso-occlusive crises when red blood cells containing HbS become deoxygenated, polymerize, and take on a rigid, sticky shape that clogs small vessels. Dehydration directly promotes this process by reducing plasma volume and increasing the concentration of hemoglobin in the blood, which raises blood viscosity and favors HbS polymerization. The result is slower flow and microvascular occlusion that causes ischemic pain, especially in bones and other richly perfused areas. Among the options, dehydration is the most direct trigger for these crises because it pushes the blood toward the conditions that favor sickling. The other factors listed don’t directly cause the vaso-occlusive mechanism: high iron intake doesn’t provoke sickling, a high white blood cell count can reflect infection that might precipitate a crisis but isn’t itself the cause, and a low platelet count isn’t a driver of vaso-occlusion.

In sickle cell disease, painful episodes come from vaso-occlusive crises when red blood cells containing HbS become deoxygenated, polymerize, and take on a rigid, sticky shape that clogs small vessels. Dehydration directly promotes this process by reducing plasma volume and increasing the concentration of hemoglobin in the blood, which raises blood viscosity and favors HbS polymerization. The result is slower flow and microvascular occlusion that causes ischemic pain, especially in bones and other richly perfused areas. Among the options, dehydration is the most direct trigger for these crises because it pushes the blood toward the conditions that favor sickling. The other factors listed don’t directly cause the vaso-occlusive mechanism: high iron intake doesn’t provoke sickling, a high white blood cell count can reflect infection that might precipitate a crisis but isn’t itself the cause, and a low platelet count isn’t a driver of vaso-occlusion.