Patients with red, swollen, painful leg may have very severe problems such as necrotizing fasciitis (infection involving muscular fascia) or infections involving muscles with or without gangrene. The patients having these infections are generally ill-looking, severely painful, and may have subcutaneous crepitations. Therefore, we should be aware of these red flags. This patient has no sign of crepitations, systemic illness, or severe pain.
Lipodermatosclerosis is chronic erythema. Patients show exacerbations because of vascular insufficiency (venous). It can be bilateral or unilateral. One of the discriminative findings from cellulitis is temperature over the lesion. Lipodermatosclerosis is not hot. In the case, the palpation showed warm skin compared to the left side.
Erysipelas is superficial and its’ borders are very sharp. The lesion is fluffy compared to the skin around the lesion. In the case, some areas of the skin were found a little bit raised compared to surrounding structures. However, its’ borders were not well-demarcated.
Other differentials are burns, contact dermatitis, urticaria, etc.