Differential Diagnosis for Painful Lump Under Ear

Single Most Likely Diagnosis

• Lymphadenitis: This is the most likely diagnosis due to the common occurrence of lymph nodes in the neck and under the ear, which can become inflamed and painful due to infection.

Other Likely Diagnoses

• Parotid Gland Infection or Abscess: The parotid gland is located under the ear, and an infection or abscess in this gland can cause a painful lump.
• Cyst or Abscess of the Skin: A skin cyst or abscess under the ear can cause a painful lump, often due to a bacterial infection.
• Lymphadenopathy due to Viral Infection: Viral infections such as mononucleosis or HIV can cause lymph nodes to become enlarged and painful.

Do Not Miss Diagnoses

• Malignant Lymphoma: Although less common, lymphoma can present with painful lymphadenopathy and must be considered to avoid delayed diagnosis.
• Parotid Gland Tumor: Both benign and malignant tumors of the parotid gland can present as a painful lump under the ear.
• Tuberculosis or Atypical Mycobacterial Infection: These infections can cause lymphadenitis that is often painful and can be located under the ear.

Rare Diagnoses

• Branchial Cleft Cyst: A congenital anomaly that can present as a painful lump under the ear, especially if it becomes infected.
• Actinomycosis: A rare bacterial infection that can cause abscesses or masses in the neck and under the ear.
• Sialolithiasis of the Parotid Gland: A condition where a stone forms in the parotid gland, which can cause a painful lump under the ear due to obstruction and infection.