Lantus Hair and Skin Changes: What Patients and Clinicians Need to Know

Insulin glargine is a long-acting human insulin analog injected subcutaneously once daily [1]. The skin and injection-site information below comes from the labels of two insulin glargine products, Semglee and Rezvoglar [1][2].

Does insulin glargine cause hair loss?

The Semglee and Rezvoglar labels name these reactions as commonly associated with insulin glargine products: hypoglycemia, allergic reactions, injection site reactions, lipodystrophy, pruritus (itching), rash, edema and weight gain [1][2].

The labels also describe changes that can follow a rapid improvement in glucose control: a transitory, reversible change in eye refraction, worsening of diabetic retinopathy and acute painful peripheral neuropathy [1]. Hair changes are not part of that description.

What skin reactions do the insulin glargine labels describe?

The Semglee and Rezvoglar labels group the skin findings with the general adverse reactions: injection site reactions, lipodystrophy, pruritus, rash and allergic reactions, alongside hypoglycemia, edema and weight gain [1][2].

Severe, life-threatening, generalized allergy, including anaphylaxis, can occur with insulins, including insulin glargine products [1][2]. The labels say to discontinue the insulin if a hypersensitivity reaction occurs, treat per standard of care and monitor until signs and symptoms resolve [1]. Both labels contraindicate the product in people with hypersensitivity to insulin glargine or any of its excipients [1][2].

Diabetes itself can also be associated with skin findings [7][8].

Lumps and dents at injection sites

Subcutaneous insulin, including insulin glargine products, has resulted in lipoatrophy, a depression in the skin, or lipohypertrophy, enlargement or thickening of tissue, in some patients [1][2].

The labels also describe a glucose consequence. Repeated insulin injections into areas of lipodystrophy or localized cutaneous amyloidosis have been reported to result in hyperglycemia, and a sudden change of injection site to an unaffected area has been reported to result in hypoglycemia [1][2]. The labels advise people who have repeatedly injected into areas of lipodystrophy or localized cutaneous amyloidosis to move to unaffected areas and monitor glucose closely [1]. More broadly, the labels warn that changing insulin strength, manufacturer, type, injection site or method of administration can affect glycemic control and predispose to hypoglycemia or hyperglycemia [1][2].

How common is lipohypertrophy?

A multicentre study by Blanco and colleagues examined injection sites in 430 outpatients who inject insulin and found lipohypertrophy in 64.4% [3]. Correct rotation had the strongest protective value: 5% of people who rotated correctly had lipohypertrophy, and 98% of those who had it either did not rotate or rotated incorrectly [3]. Risk rose with needle reuse, increasing significantly when needles were used more than five times, and mean total daily insulin was 56 units in people with lipohypertrophy versus 41 units in those without [3].

A second study of 215 people who had used insulin for at least two years found lipohypertrophy in 48.8%. Time on insulin, how often injection sites were changed and how often needles were changed were all significant factors [4]. Both studies looked at insulin injectors in general rather than insulin glargine alone.

What injection technique recommendations say

The Forum for Injection Technique and Therapy recommendations were written and vetted by 183 diabetes experts from 54 countries [5]. They state that the shortest needles, currently 4-mm pen needles and 6-mm syringe needles, are safe, effective and less painful and should be first-line in all patient categories; that intramuscular injection should be avoided, especially with long-acting insulins, because severe hypoglycemia may result; and that lipohypertrophy distorts insulin absorption, so injections should not be given into these lesions and correct site rotation helps prevent them [5].

The insulin glargine labels give the same core instruction: rotate injection sites within the same region from one injection to the next to reduce the risk of lipodystrophy and localized cutaneous amyloidosis, and do not inject into areas of lipodystrophy or localized cutaneous amyloidosis [1][2].