Differential Diagnosis for Vesicular Lesions on the Right Face

The patient presents with vesicular-like lesions on the right face, extending from the ear to the chin, accompanied by painful blisters, mild erythema, warmth, and pain. The following differential diagnoses are considered:

• Single Most Likely Diagnosis

  • Herpes Zoster (Shingles): This condition is characterized by a painful rash, typically affecting one side of the body, which matches the patient's presentation. The rash usually starts as red spots that quickly turn into blisters, fitting the description of painful blisters surrounded by mild erythema and warmth.

• Other Likely Diagnoses

  • Contact Dermatitis: This could be a possibility if the patient has come into contact with an allergen or irritant on the right side of the face, leading to an allergic reaction or irritation that presents with vesicles, erythema, and pain.
  • Eczema (Atopic Dermatitis): Although less common to present unilaterally, eczema can cause vesicular lesions, especially in acute phases, accompanied by erythema and pain.
  • Impetigo: A bacterial infection of the skin that can cause vesicles or pustules, often with surrounding erythema and warmth, though it's less likely to be confined strictly to one side of the face without a clear reason.

• Do Not Miss Diagnoses

  • Lyme Disease: Early stages can present with a distinctive "bull's-eye" rash (erythema migrans), but it can also appear as vesicular lesions in some cases. Given its potential for serious complications if untreated, it's crucial not to miss this diagnosis.
  • Cellulitis: An infection of the skin and subcutaneous tissues that can present with erythema, warmth, and pain. While it typically does not cause vesicles, in severe cases, it can lead to blistering, and its potential for serious complications warrants consideration.

• Rare Diagnoses

  • Pemphigus Vulgaris: An autoimmune disease causing blistering of the skin and mucous membranes. It's rare and usually involves the mouth first, but it can present with skin lesions that might fit the patient's description.
  • Bullous Pemphigoid: Another autoimmune blistering disease that is rare and typically affects older adults, presenting with large blisters that can be filled with fluid, though it's less common to be unilateral and localized to the face.
  • Dermatitis Herpetiformis: A skin manifestation of celiac disease, characterized by intensely itchy blisters, which could be considered if the patient's symptoms persist and other diagnoses are ruled out.