From pinprick to peril: digital ischemia and necrosis of fingertips induced by routine capillary glucose testing

Article information

Korean J Intern Med. 2024;39(3):541-542

Publication date (electronic) : 2024 January 26

doi : https://doi.org/10.3904/kjim.2023.370

Wan-Hee Yoo^1,2, Yunjung Choi^1,2

¹Division of Rheumatology, Department of Internal Medicine, Jeonbuk National University Medical School, Jeonju, Korea

²Research Institute of Clinical Medicine of Jeonbuk National University - Biomedical Research Institute, Jeonbuk National University, Jeonju, Korea

Correspondence to: Yunjung Choi, M.D., Ph.D., Division of Rheumatology, Department of Internal Medicine, Jeonbuk National University Medical School, 20 Geonji-ro, Deokjin-gu, Jeonju 54907, Korea, Tel: +82-63-250-1671, Fax: +82-63-254-1609, E-mail: imcyj@jbnu.ac.kr

Received 2023 August 31; Revised 2023 September 27; Accepted 2023 October 23.

A 63-year-old woman with a history of myasthenia gravis, hypertension, and diabetes was referred from Neurology to our department for fingertip lesions evaluation. During her 2-month hospitalization for myasthenia gravis management, she expressed concern about an unexpected lesion on her fingertip that progressively increased in size.

Physical examination revealed no significant lesions on her left hand. However, her right hand’s fingertips displayed variations in skin color from dark brown to black, with advancing necrotic changes, notably on the 5th finger (Fig. 1). Both fingers exhibited pallor from the distal to proximal interphalangeal joint, accompanied by noticeable coldness. Assessment indicated a skin thickness corresponding to a modified Rodnan Skin Score of 2. The patient presented a history of Raynaud’s phenomenon spanning several years. Laboratory analysis revealed an elevated ANA titer of 1:1,280 and anti-centromere antibody level of 63 IU/mL, leading to the definitive systemic sclerosis diagnosis.

Figure 1

Fingertip ischemia and necrosis in the right hand of a patient with systemic sclerosis following repetitive finger-stick glucose testing. The bilateral fingers exhibited a pallid hue accompanied by the progressive manifestation of cutaneous sclerosis. Particularly noteworthy, the distal phalanges of the right hand—where repetitive capillary glucose testing had been conducted—unveiled conspicuous ischemic transformations, characterized by a spectrum of discoloration spanning from deep brown to ebony black, indicative of incipient necrotic changes.

Despite no recorded trauma, consistent blood glucose testing was conducted on her right hand’s fingers during hospitalization. This suggests that the manifestation of ischemia and necrosis in fingertip regions, particularly where glucose testing was performed, originated from repetitive capillary microinjuries. Despite intravenous prostanoid therapy, progressive necrotic changes in the fifth finger necessitated surgical intervention, leading to the amputation of the distal phalanx.

Systemic sclerosis, an autoimmune connective tissue disease, features fibrosis and vasculopathy. Digital vasculopathy ranges from Raynaud’s phenomenon to ulcers, and necrosis. Mechanical microtrauma alongside ischemia can trigger ulceration [1], causing pain, disability, and tissue loss. Thus, enhancing awareness and prioritizing preventive measures are of utmost importance [2].

Glucose monitoring is pivotal in diabetes management, often involving capillary glucose testing at the fingertips. However, our case study underscores potential complications, including ulceration and necrosis, specifically in systemic sclerosis patients. Consequently, it becomes paramount for clinicians to acknowledge these vulnerabilities among systemic sclerosis patients.