Differential Diagnosis for Pustule on Flexural Fold
- Single most likely diagnosis
- Intertrigo: This is the most likely diagnosis due to the location on the flexural fold, which is a warm, moist area prone to friction and irritation, creating an ideal environment for intertrigo to develop.
- Other Likely diagnoses
- Eczema (atopic dermatitis): Flexural areas are commonly affected in atopic dermatitis, and pustules can occur, especially if there is a secondary bacterial infection.
- Contact dermatitis: Irritant or allergic contact dermatitis can cause pustules in flexural areas due to exposure to offending agents.
- Folliculitis: An infection of the hair follicles, which can present with pustules and is more common in areas with high hair density, including some flexural areas.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Cellulitis: Although less likely to present initially as a single pustule, cellulitis is a serious infection that requires prompt treatment. It can start in flexural areas and spread rapidly.
- Necrotizing fasciitis: A severe, life-threatening infection that can start with minimal skin findings, including a pustule, but rapidly progresses. Early recognition is crucial.
- Rare diagnoses
- Pustular psoriasis: While more commonly associated with extensor surfaces, pustular psoriasis can occasionally present in flexural areas, especially in the context of generalized pustular psoriasis.
- Acrodermatitis enteropathica: A rare genetic disorder that can cause pustular skin lesions, including in flexural areas, along with gastrointestinal and other systemic symptoms.
- Hiddenitis suppurativa: Characterized by recurrent, painful pustules and nodules in apocrine-gland-bearing areas, including flexural regions. It's more chronic than acute and can be debilitating if not properly managed.