Differential Diagnosis for Small, Red Sores on the Face
- Single Most Likely Diagnosis
- Impetigo: This is the most likely diagnosis given the description of small, red sores that started as a single lesion and gradually increased in number, along with itching and no pain. The pediatrician's initial suspicion of impetigo also supports this diagnosis.
- Other Likely Diagnoses
- Contact Dermatitis: This could be a possibility if the patient came into contact with an allergen or irritant, especially given her frequent interactions with other children at the playground.
- Eczema (Atopic Dermatitis): Although the patient denies bug bites, eczema could still be a consideration, especially if she has a history of atopic diseases.
- Folliculitis: This is an inflammation of the hair follicles and could present with small, red sores, especially if the patient has been scratching the area due to itching.
- Do Not Miss Diagnoses
- Cellulitis: Although less likely given the description of small, discrete sores, cellulitis is a serious infection that requires prompt treatment. It's essential to consider this diagnosis to avoid missing a potentially severe condition.
- Herpes Simplex Virus (HSV): HSV can cause small, painful blisters, but the patient denies pain. However, it's crucial to consider HSV due to its potential for serious complications, such as herpetic keratitis.
- Varicella (Chickenpox): Although the patient doesn't report exposure to anyone with similar symptoms, varicella is highly contagious and can have severe consequences if missed, especially in immunocompromised individuals.
- Rare Diagnoses
- Pityriasis Rosea: This is a rare skin condition characterized by a rash that starts with a single lesion, followed by the development of multiple smaller lesions. However, it typically starts on the trunk and spreads to other areas, making it less likely in this case.
- Gianotti-Crosti Syndrome: This is a rare condition that presents with a rash and is often associated with hepatitis B or other viral infections. It's unlikely but should be considered if other diagnoses are ruled out.