Allergic Otitis Externa: This condition is characterized by an allergic reaction in the ear canal, often due to exposure to allergens like pollen, dust, or certain metals in earrings. Itching and soreness are common symptoms, making it a likely diagnosis for a 22-year-old female with a month-long history of these symptoms.

Seborrheic Dermatitis: This is a skin condition that can affect the ears, causing itching and soreness due to inflammation. It's common in young adults and can be managed with topical treatments.
Eczematous Otitis Externa: Similar to allergic otitis externa but not necessarily triggered by an allergic reaction. It involves inflammation of the ear canal, leading to itching and soreness.
Fungal Otitis Externa: A fungal infection of the ear canal, which can cause itching, soreness, and sometimes a discharge. It's more common in warm, humid environments or after swimming.

Malignant Otitis Externa: Although rare, this condition is a severe infection of the ear canal and surrounding bone and cartilage. It's more common in diabetic or immunocompromised patients but can occur in anyone. It requires prompt medical attention due to the risk of serious complications.
Middle Ear Infection (Otitis Media): While less likely to present primarily with itching, a middle ear infection can cause discomfort that might be perceived as soreness and could potentially lead to itching due to associated Eustachian tube dysfunction.

Relapsing Polychondritis: A rare autoimmune disorder that can cause inflammation and destruction of cartilaginous structures, including those in the ear. It might present with ear pain and could potentially cause itching due to the inflammatory process.
Keratosis Obturans: A condition where desquamated skin accumulates in the ear canal, potentially causing itching, soreness, and sometimes hearing loss. It's less common and might be considered if other diagnoses are ruled out.