FIGURE 66.6 Erysipelas (Reprinted with permission from Frontera WR FIMS Sports Medicine Manual Philadelphia, PA: Lippincott Williams & Wilkins; 2011.) Cellulitis Cellulitis is the acute presentation of red, painful, swollen skin that is caused by a localized bacterial infection in the dermis and subcutaneous tissue There may have been a break in the skin that leads to the infection but the infection then spreads underneath the skin Because the infection is within the skin, it is difficult to culture the pathogen Leading edge cultures have a low yield so most patients are treated empirically Patients with disruption of the skin barrier (e.g., tinea pedis or atopic dermatitis) or lymphatic disruption (postsurgical or from a congenital lymphatic abnormality) have a higher risk of cellulitis Erysipelas is a type of cellulitis that presents with swollen, red, painful edematous plaques due to infection of the superficial dermal lymphatics ( Fig 66.6 ) In erysipelas, there is often a step-off from affected edematous to normal skin The differential diagnosis of cellulitis includes contact dermatitis Contact dermatitis is often multifocal and itchy Looking for linear areas of redness or vesiculation can help favor a contact allergy Acute contact dermatitis of the