Which symptom is characteristic of descending paralysis in botulism?

The characteristic symptom of descending paralysis in botulism is indeed descending facial paralysis. Botulism, caused by the toxin produced by Clostridium botulinum, leads to a unique pattern of muscle weakness that starts in the cranial nerves and progresses downwards. This means that symptoms such as facial paralysis occur early, affecting the muscles of the face and throat.

As the disease progresses, it can lead to weakness in the arms and legs, consistent with the descending pattern of paralysis. The altered neurologic function can also manifest in difficulties with swallowing (dysphagia) and breathing due to the involvement of the respiratory muscles. However, the defining feature of botulism is the descent of paralysis from the head downward, which aligns with the characteristic facial paralysis that signifies the onset of the illness.

Fever is typically absent in botulism since it is a result of a neurotoxin rather than an infectious process. Thus, seeing descending facial paralysis is a clear indication of botulism's impact on neuromuscular function.