Linda is a 78-year-old woman with a history of severe venous…

Linda is a 78-year-old woman with a history of severe venous stasis. She presents for follow up of treatment of cellulitis to her lower extremities. She has completed not just one, but two different appropriate antibiotics for skin infection but continues to complain of significant tenderness, redness and discomfort. The tissue feels indurated, mild erythema, no abscess or increased warmth. The skin appears intact without noted disruption. In addition to cellulitis, what might you consider in her differential diagnoses as a causative etiology of this issue?