Insulin injection: cutaneous adverse effects

Sir,

We read with great interest the article published in May–June 2015 issue by Tandon et al. titled “The Indian recommendations 2.0, for best practice in insulin injection technique 2015.”[1]

Authors have nicely highlighted the correct insulin injection techniques and its importance. Proper insulin administration is equally important as the correct type and dosage of insulin. In routine practice this vital aspect of demonstrating the technique of insulin injection and counseling of the patients if often overlooked. The inappropriately administered insulin not only leads to deranged blood glucose but can lead to many cutaneous adverse effects.

Local dermal reactions at the site of insulin therapy occur at some point of time in about half of all diabetes patients.[2] Apart from the mentioned adverse effects, some other cutaneous adverse effects needs to be highlighted. Acanthosis nigricans localized at the site of insulin injection is one of the commonly observed adverse effect over sites such as abdomen and arms.[3] Acanthosis nigricans co-localizing with amyloidosis have also been reported following insulin injections.[4]

Postinflammatory hyperpigmentation is also one of the common cutaneous adverse effects following insulin injections, which can have at times a very bizarre presentation. We observed a young female having a whorled pattern postinflammatory hyperpigmentation over abdomen and buttocks, the site of insulin injections [Figure 1a and b]. The patient used to get insulin injections (premixed insulin [human mixtard 30:70]) through her father, reutilizing the needles several times. Multiple use of needles makes the needlepoint blunt. This blunt tipped needle produces more micro-trauma leading to postinflammatory hyperpigmentation. This strange pattern of pigmentation caused a serious cosmetic disfigurement and embarrassment, deterring this young female patient to continue the insulin injections.

Figure 1.

(a) Numerous, discrete well-defined, round, monomorphic, brown to black, macular lesions present in a whorl pattern, over the abdomen. (b) Multiple, brown to black macular lesion over both buttocks

This highlights the importance of patient's counseling and education regarding proper technique of insulin administration in order to avoid such complications and achieve a normal blood glucose level.