A man in his 50s with type 1 diabetes mellitus presented with a 3-month eruption of small reddish brown spots affecting most of his fingers. The lesions were persistent, asymptomatic, and without aggravating or alleviating factors. The patient used standard finger sticks to test his blood glucose levels daily. However, he had pricked his fingers for decades without incident. A review of symptoms was positive only for intermittent bloating and diarrhea. Physical examination revealed multiple petechiae in a linear arrangement extending from the volar and lateral aspects of the fingers to the finger pads (Figure, A). Results from initial laboratory tests, including a complete blood cell count, comprehensive metabolic panel, antinuclear antibody, erythrocyte sedimentation rate, rheumatoid factor, and cardiolipin antibody, were unremarkable. Results from a urinalysis and transthoracic echocardiogram were also unremarkable. Punch biopsies for histopathologic examination (Figure, B) and direct immunofluorescence (Figure, C) were performed.
Zaghi D, Witheiler D, Menter AM. Petechial Eruption on Fingers. JAMA Dermatol. 2014;150(12):1353-1354. doi:10.1001/jamadermatol.2014.2278