Differential Diagnosis for Crusted Vesicles on Forehead
- Single most likely diagnosis
- Impetigo: This is a highly contagious bacterial skin infection that often presents with crusted vesicles or pustules, commonly on the face, including the forehead. It's caused by Staphylococcus aureus or Streptococcus pyogenes.
- Other Likely diagnoses
- Herpes simplex virus (HSV) infection: Although more commonly associated with oral or genital areas, HSV can cause lesions on the forehead, especially if there's a history of similar outbreaks or exposure.
- Contact dermatitis: An allergic reaction or irritant contact dermatitis could lead to vesicular lesions on the forehead, especially if the individual has been exposed to new skincare products, makeup, or other potential allergens.
- Eczema (atopic dermatitis): This chronic condition can cause dry, itchy skin and sometimes vesicles, particularly in individuals with a history of atopic diseases.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Varicella-zoster virus (VZV) reactivation (shingles): Although less common on the forehead, shingles can present with a vesicular rash and is important to diagnose due to the potential for serious complications, such as postherpetic neuralgia or ocular involvement if the rash affects the area around the eye.
- Meningococcemia: This severe infection can cause a petechial or vesicular rash and is a medical emergency. Early recognition and treatment are crucial to prevent high mortality.
- Rare diagnoses
- Pemphigus vulgaris: An autoimmune disease that can cause blistering of the skin and mucous membranes. It's rare but important to consider due to its potential severity and need for specific treatment.
- Bullous pemphigoid: Another autoimmune blistering disease that, although rare, could present with vesicles on the forehead among other areas of the body.
- Dermatitis herpetiformis: A skin manifestation of celiac disease, characterized by intensely itchy, blistering skin. It's less common but should be considered, especially if there are gastrointestinal symptoms or a family history of celiac disease.