Insulin induced lipoatrophy

K Krishna, RP Mane, K Kavita

 Department of Medicine, Bharati Vidyapeeth Deemed University Medical College & Bharati Hospital, Dhankawadi, Pune - 411043, India

Correspondence Address:
K Krishna
23, Sopan Baug Cooperative Housing Society, Pune - 411001
India

Sir,

Insulin induced lipoatrophy is becoming increasingly uncommon.[1] We came across a 14-year-old girl with insulin induced lipoatrophy presenting as depressed atrophic plaques over thighs and abdomen at the site of repeated self-administered insulin injections.

The patient suffered from insulin dependent diabetes mellitus (DM) since the age of 6 years. Her random blood sugar level at first presentation was 380 mg%. She was initially treated with bovine insulin injections, initially short acting, then long acting, for 3 years. However she developed dimpling and depressed plaques over the anterior aspect of both thighs at the site of the injections, suggestive of insulin lipoatrophy. Since the therapeutic response to bovine insulin injection was unsatisfactory, she was treated with a long acting porcine insulin preparation for the next 2 years. However, she continued to develop bilaterally symmetrical, unsightly depressed plaques over both thighs [Figure - 1]. She was advised to change the injection site to the abdomen to avoid repeated injections in the thighs. She then developed similar atrophy of the subcutaneous fat on either side of the midline on the abdomen [Figure - 1]. She has subsequently been using a purified human insulin preparation (a mixture of long acting and short acting insulins) since the last 3 years. The lipoatrophy has not progressed further, and she has achieved better control of her blood sugar level with purified insulin injections and strict adherence to dietary advice.

Insulin lipoatrophy presents as depressed plaques, histologically showing atrophy of the subcutaneous fat.[2] It is an allergic phenomenon, thought to be due to immune complex deposition. IgG and insulin have been demonstrated in lipoatrophic tissues, and circulating anti-insulin antibody titres are commonly high. It is treated by injections of highly purified soluble insulin, which floods the site with antigen and solubilizes the complexes.[1]

Lipoatrophy localized to injection sites occurs particularly with longer acting preparations. It is becoming more and more infrequent with the use of modern insulins.[1]

1.	Pickup JC, Williams G. Insulin injection treatment and its complications. In: Pickup JC, Williams G, editors. Textbook of Diabetes. 2nd ed. Oxford: Blackwell Science; 1998. p. 33.1-33.20. [Google Scholar]
2.	Fleming MG, Simon SI. Cutaneous insulin reaction resembling acanthosis nigricans. Arch Dermatol 1986;122:1054-6. [Google Scholar]