Differential Diagnosis for Unilateral Facial Swelling
The patient's presentation of unilateral eyelid swelling that spread to the face and neck, along with a history of eczema and a recent whole-body flare-up, suggests an allergic or autoimmune etiology. The failure of histamine and steroids to improve symptoms complicates the diagnosis. Here's a categorized differential diagnosis:
Single Most Likely Diagnosis
- Contact Dermatitis or Allergic Contact Dermatitis: Given the patient's history of eczema and the unilateral nature of the swelling, an allergic reaction to a substance that came into contact with the right side of the face is plausible. The recent whole-body eczema flare could be coincidental or related to the same allergen.
Other Likely Diagnoses
- Angioedema: Although the patient failed histamine and steroids, angioedema, especially if hereditary, could present with recurrent episodes of swelling. The unilateral nature and the involvement of the face and neck are consistent with this diagnosis.
- Cellulitis or Erysipelas: Bacterial infections could cause unilateral facial swelling, especially if there's a history of trauma or infection. However, the lack of response to steroids and the presence of eczema might suggest otherwise.
- Vasculitis (as suggested by another provider): Conditions like granulomatosis with polyangiitis (formerly known as Wegener's granulomatosis) could present with facial swelling, but the patient's symptoms and lack of systemic findings (e.g., renal involvement, respiratory symptoms) make this less likely.
Do Not Miss Diagnoses
- Lymphoma or Other Malignancies: Although rare, lymphomas can present with localized swelling due to lymph node involvement. Given the patient's age and the unilateral nature of the symptoms, this is a diagnosis that should not be missed, despite its low likelihood.
- Infectious Causes (e.g., Lyme Disease, Tuberculosis): Certain infections can cause localized swelling and should be considered, especially if the patient has been exposed to ticks (for Lyme disease) or has traveled to areas where tuberculosis is common.
Rare Diagnoses
- Sjögren's Syndrome: An autoimmune disorder that could potentially cause localized swelling, although it more commonly presents with dry eyes and mouth.
- Melkersson-Rosenthal Syndrome: A rare neurological disorder characterized by recurrent, often unilateral, facial paralysis or swelling, along with other symptoms like fissured tongue. The patient's presentation could be a variant, but the syndrome's rarity and the lack of other characteristic symptoms make it less likely.