55 years old uncontrolled diabetic patient presents with fever and severe pain in the right ear with active pus discharge since three days. On examination granulation tissue is evident in the external auditory canal. What is the most probable diagnosis?
**Core Concept**
Diabetic patients are prone to developing external auditory canal infections, particularly those involving the external auditory canal's epithelial lining. The presence of granulation tissue in the external auditory canal is indicative of a chronic infection.
**Why the Correct Answer is Right**
The clinical presentation of fever, severe pain, and active pus discharge in the right ear, along with granulation tissue in the external auditory canal, is highly suggestive of a malignant otitis externa. This condition is a severe, potentially life-threatening infection that predominantly affects diabetic patients. The infection spreads to the cartilaginous and bony structures of the external auditory canal, leading to the formation of granulation tissue and tissue destruction.
The underlying pathophysiology involves the spread of bacteria, such as Pseudomonas aeruginosa, through the external auditory canal, facilitated by the compromised immune system of diabetic patients. The bacteria cause a severe inflammatory response, leading to tissue destruction and the formation of granulation tissue.
**Why Each Wrong Option is Incorrect**
**Option A:** Otitis externa without granulation tissue is not as severe and does not typically present with fever and pus discharge.
**Option B:** Malignant otitis media is a condition that affects the middle ear, not the external auditory canal, and is typically seen in patients with compromised immune systems, such as those with HIV/AIDS.
**Option C:** Eczema of the external auditory canal can cause discomfort and itching, but it does not typically present with fever and pus discharge.
**Clinical Pearl / High-Yield Fact**
Diabetic patients with uncontrolled blood sugar levels are at increased risk of developing malignant otitis externa, a potentially life-threatening infection that requires prompt medical attention.
**Correct Answer:** C. Malignant otitis externa.