Differential Diagnosis for a Boil on a 4-Year-Old
Single Most Likely Diagnosis
- Furuncle (Boil): This is the most common diagnosis for a localized, painful, and swollen lesion on the skin, especially if it has a central pus-filled core. It is usually caused by Staphylococcus aureus.
Other Likely Diagnoses
- Folliculitis: An inflammation of the hair follicles, which can be caused by bacterial, viral, or fungal infections. It presents similarly to a boil but is typically less severe and may not have a central pus core.
- Impetigo: A highly contagious skin infection that can cause red sores, especially on the face, but can occur anywhere on the body. It's more superficial than a boil and often has a golden crust.
- Cellulitis: A bacterial skin infection that causes redness, swelling, and pain. While it can present similarly to a boil, it tends to be more diffuse and not localized to a single area.
Do Not Miss Diagnoses
- Methicillin-Resistant Staphylococcus aureus (MRSA) Infection: Although less common, MRSA infections can present as boils or abscesses and are critical to identify due to their resistance to common antibiotics, requiring specific treatment.
- Erysipelas: A type of skin infection that involves the upper dermis, typically caused by Streptococcus bacteria. It presents with well-demarcated, raised, and shiny lesions and can be more serious, especially in young children.
- Orbital Cellulitis: If the boil is near the eye, there's a risk of orbital cellulitis, a serious infection of the tissues surrounding the eye that can lead to severe complications, including vision loss.
Rare Diagnoses
- Hydradenitis Suppurativa: A chronic skin condition characterized by recurring, painful abscesses and nodules, typically in areas with apocrine glands like the armpits or groin. It's rare in young children.
- Actinomycosis: A rare bacterial infection that can cause abscesses, but it's more commonly associated with the face and neck and has a distinctive presentation with sinus tracts and a history of oral procedures or trauma.
- Cutaneous Leishmaniasis: A parasitic infection that can cause skin lesions, but it's rare in areas without endemic Leishmaniasis and typically has a history of travel to such areas.