**Question:** Pathognomic features of Maxillary sinusitis is

A. Swollen and red mucosal membrane
B. Nasal obstruction
C. Discharge from the maxillary sinus oronasally
D. Facial pain

**Core Concept:**
Maxillary sinusitis is a type of sinusitis affecting the maxillary sinuses, which are located in the maxilla bone, between the eyes and teeth. The primary pathognomic features of maxillary sinusitis are:

1. **Swollen and red mucosal membrane:** Inflammation of the mucosal membrane lining the maxillary sinus is a hallmark of maxillary sinusitis. This inflammation can cause swelling and a reddish appearance, which is indicative of infection or inflammation.
2. **Nasal obstruction:** Nasal obstruction is a common symptom of maxillary sinusitis. The inflamed mucosa can obstruct the natural drainage pathways of the maxillary sinus, leading to sinusitis.
3. **Discharge from the maxillary sinus oronasally:** Discharge from the affected sinus can be observed oronasally (through the nose or mouth). This discharge may be clear, purulent, or mixed, depending on the causative agent and stage of infection.
4. **Facial pain:** Pain in the maxillary region can be a manifestation of maxillary sinusitis. This pain may be referred from the infected sinus to the teeth, eye, or cheek, making it important to differentiate it from dental, orbital, or tooth pain.

**Why the Correct Answer is Right:**

The correct answer, which includes swelling and redness of the mucosal membrane, nasal obstruction, discharge from the maxillary sinus oronasally, and facial pain, accurately describes the key clinical features of maxillary sinusitis. These features help differentiate maxillary sinusitis from other conditions affecting the maxillary region, such as dental abscess, orbital cellulitis, or toothache.

**Why Wrong Answer Options are Incorrect:**

Option A (Facial ptosis) and Option B (Facial swelling) are incorrect because ptosis refers to drooping of the eyelid, while swelling can occur due to other causes like inflammation, infection, or trauma. These features are not specific to maxillary sinusitis.

Option C (Fever) is partially correct, as fever can be present in maxillary sinusitis, but it is not a defining feature of the condition. Other causes like dental infection or orbital cellulitis may also present with fever, making it a less reliable feature for diagnosis.

Option D (Nasal obstruction) is partially correct, as nasal obstruction can be present in maxillary sinusitis, but it is not specific to this condition. Nasal obstruction can result from various conditions affecting the nasal cavity or the sinuses, making it an insufficient diagnostic criterion.

**Clinical Pearls:**

1. **Facial pain and nasal discharge are often present in maxillary sinusitis.** These features are more specific to maxillary sinusitis compared to other causes of facial pain, such as dental abscess or toothache.
2. **Anterior rhinorrhea (nasal discharge)** can be seen in maxillary sinusitis, which is a common feature of this condition.