The main diagnoses to consider are.
Cellulitis: manifests as diffuse, edematous, infiltrative erythema with indistinct borders, high local skin temperature and marked central erythema, which may be accompanied by chills and hyperthermia in the acute phase.
Intermittent rubbing rash: it occurs in obese people and infants, mostly in high temperature and high humidity weather, and it occurs in easily rubbed and moist folds such as groin, neck, underarm, under breast, flexor side of joints, etc. It is a limited bright red or dark red spot with clear boundaries at first, and papules, papules, maceration and vesicles appear in gradual aggravation.