Clinical sign seen in tetanus –

Correct option is C

Sol. Opisthotonus is a classical sign of severe tetanus characterized by extreme hyperextension and rigidity of the body due to continuous, powerful muscle spasms. It is caused by tetanospasmin, a neurotoxin produced by Clostridium tetani, which blocks inhibitory neurotransmitters like GABA. This leads to unopposed muscle contractions and spasms. The posture typically includes arching of the back and neck, clenched fists, and rigid limbs. It usually occurs in advanced or untreated tetanus. Prompt treatment with antitoxins and muscle relaxants is necessary. Immunization remains the most effective preventive strategy.
Explanation of each option:
· (a) Koplik’s spot – Seen as tiny white lesions on the buccal mucosa, they are a hallmark of measles, not tetanus.
· (b) Pseudomembrane – This thick gray membrane is a feature of diphtheria, usually found over the tonsils or pharynx.
· (c) Opisthotonus – Correct. This is a hallmark feature of advanced tetanus and indicates serious neurotoxic involvement.
· (d) Hydrophobia – Seen in rabies, not tetanus. It refers to fear of water due to painful throat spasms during swallowing.