Which of the following is NOT a potential cause of impairment to touch?

• A. Stroke
• B. Nerve injury
• C. Allergic reaction
• D. Laceration

Answer: (C)

Touch depends on receptors in the skin and the neural pathways that carry those signals to the brain. When these pathways are damaged or the receptors are affected, touch can be impaired. Stroke can disrupt the brain areas that process touch, leading to loss or alteration of sensation. Nerve injury directly interrupts the transmission of tactile information along peripheral nerves, causing numbness or reduced touch in the affected region. A laceration can physically damage skin and the underlying nerves, producing localized loss of touch where the cut occurred. An allergic reaction, on the other hand, mainly causes itching, redness, swelling, or hives as part of an immune response; it does not typically impair tactile sensation. Therefore, an allergic reaction is not a usual cause of impaired touch.