Differential Diagnosis

The patient's symptoms of infrequent, non-painful, tense, dome-shaped, fluid-filled blisters that are itchy, rupture with yellow clear discharge, and self-resolve within a few days, particularly on the arms, legs, or stomach, and more commonly in spring/summer, suggest several potential diagnoses. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis
  • Bullous Pemphigoid: This is an autoimmune skin disease characterized by the formation of blisters. The description of tense, fluid-filled blisters that are itchy and resolve without scarring, especially in a seasonal pattern, aligns with bullous pemphigoid. The disease often affects older adults and can have a remitting-relapsing course.
• Other Likely Diagnoses
  • Dyshidrotic Eczema (Pompholyx): Although typically more painful and involving the hands and feet, some presentations can be less typical, and the seasonal variation could fit with exacerbations due to environmental factors.
  • Bullous Dermatitis: A condition that can present with fluid-filled blisters, though it's less common and might not fully explain the seasonal pattern and specific locations.
• Do Not Miss Diagnoses
  • Epidermolysis Bullosa Acquisita (EBA): An autoimmune disease that can cause blisters, which might resemble those described. It's crucial to consider due to its potential for significant morbidity if not treated properly.
  • Bullous Systemic Lupus Erythematosus: Although rare, this condition can cause blistering skin lesions and is a diagnosis that should not be missed due to the systemic implications of lupus.
• Rare Diagnoses
  • Linear IgA Bullous Dermatosis: An autoimmune condition characterized by blistering skin lesions. It's less common and might present with a variety of symptoms, including those described.
  • Porphyria Cutanea Tarda: A disorder that can lead to blistering of the skin upon sun exposure, which could explain the seasonal pattern of symptoms. However, it typically involves more areas and has additional symptoms like hypertrichosis and hyperpigmentation.

Each of these diagnoses has a different set of implications for treatment and management, emphasizing the importance of a thorough diagnostic workup, potentially including skin biopsy and immunofluorescence studies, to accurately determine the cause of the patient's symptoms.