A male Shyam, age 30 years presented with Trismus, fever, swelling pushing the tonsils medially and spreading laterally posterior to the middle sternocleidomastoid. He gives an h/o excision of 3rd molar a few days back for dental caries. The diagnosis is –
**Core Concept**
Parotid gland inflammation, commonly known as parotitis, can be caused by a bacterial infection, typically Staphylococcus aureus or Streptococcus pyogenes, or a viral infection, such as mumps. However, the presentation in this case, particularly the trismus (difficulty opening the mouth) and the specific location of the swelling, suggests a different diagnosis.
**Why the Correct Answer is Right**
The clinical presentation of trismus, fever, and swelling spreading laterally posterior to the middle sternocleidomastoid muscle, in a patient with a recent history of dental surgery, is highly suggestive of a **parapharyngeal abscess**. This type of abscess occurs in the space between the pharynx and the lateral pharyngeal wall, and can cause the pharynx to be displaced medially. The recent dental surgery likely introduced bacteria into the parapharyngeal space, leading to an abscess. The trismus is likely due to the swelling of the pterygoid muscles, which are involved in the movement of the jaw.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not match the clinical presentation of trismus, fever, and swelling in the parapharyngeal space.
* **Option B:** This option is incorrect because it refers to a diagnosis that is not consistent with the patient's symptoms and history.
* **Option C:** This option is incorrect because it refers to a diagnosis that is not consistent with the patient's symptoms and history.
**Clinical Pearl / High-Yield Fact**
A parapharyngeal abscess can be a serious and potentially life-threatening condition if not treated promptly, and should be suspected in any patient with a recent history of dental surgery and symptoms of trismus, fever, and swelling in the lateral pharyngeal wall.
**Correct Answer: C. Parapharyngeal abscess.**