The differential diagnoses for purpuric or petechial lesions on bilateral toes are hypercoagulable conditions, thrombotic or embolic process, vasculitis, and chilblains (also known as pernio or perniosis). Perniosis associated with lupus erythematosus is probably the most important condition in differential diagnosis because cutaneous lesions can be similar. Therefore, it is beneficial to do antinuclear antibody screen when there is a clinical suspicion or family history of a rheumatologic disorder.

Chilblains are itchy, tender, red or purple papules that occur in response to prolonged cold exposure. The lesions start as red areas with itching and burning a few hours after cold exposure and typically resolve in 7–14 days but may thicken and persist for months [9]. The small blood vessels constrict with cold exposure, and the blood leaks into surrounding tissues with rewarming. It is more common in children, women, and elderly people. It is seen almost exclusively in the winter months and in damp or wet, cold conditions. There can be a positive family history of chilblains. It has also been associated with smoking, hyperlipidemia, low body weight, poor nutrition, connective tissue diseases (most commonly lupus), cryoglobulins, and cold agglutinin disease [10]. Lesions most commonly occur on the fingers, toes, nose, and ears.

Chilblains are usually a clinical diagnosis; however, if necessary, a skin biopsy may be performed. It is also important to rule out associated conditions. It responds poorly to treatment, but the lesions usually resolve in 7–14 days without any specific treatment. Treatment options include a 2- to 3-day course of topical corticosteroid cream, which may also help with itching and swelling. Topical or oral antibiotics may be used for any secondary infection. For chilblains, prevention is the key, including avoidance of smoking, secondhand smoke exposure, or medications that cause blood vessel constriction, such as decongestants. Keeping the extremities warm and dry and wearing wool or moisture-resistant socks and mittens may help prevent development of new lesions or exacerbation of existing ones. In extreme cases, nifedipine (vasodilator) may be prophylactically prescribed before the onset of cold weather and taken throughout the winter season [11]. Prognosis is very good in children with complete recovery seen in a majority [12].