What should I do if I experience itching all over my body after injecting Solostar (insulin glargine) Lantus?

Immediate Management of Generalized Itching After Lantus (Insulin Glargine) Injection

Stop the insulin glargine injection immediately and seek urgent medical evaluation, as generalized itching (pruritus) following insulin injection suggests a systemic hypersensitivity reaction that can progress to anaphylaxis. 1, 2

Immediate Actions Required

Assess for signs of anaphylaxis right now:

• Check for difficulty breathing, wheezing, or throat tightness 3
• Look for widespread hives (urticaria), facial swelling (angioedema), or rash 2
• Monitor for dizziness, hypotension, chest pain, or rapid heartbeat 3
• Evaluate for nausea, vomiting, or abdominal cramping 3

If any of these severe symptoms are present, call emergency services immediately and use epinephrine if available. 3

Understanding This Reaction

Insulin allergy is rare but well-documented with insulin glargine (Lantus):

• True IgE-mediated allergic reactions can cause generalized symptoms including widespread itching, urticaria, angioedema, and potentially anaphylaxis 1, 2
• Reactions typically occur within minutes to hours after injection, though they can develop after multiple exposures 2
• The allergy may be to the insulin molecule itself or to excipients (additives) in the formulation 1

Symptomatic Treatment While Awaiting Medical Care

For mild itching without other concerning symptoms:

• Take an oral H1-antihistamine immediately (cetirizine 10mg, loratadine 10mg, or diphenhydramine 25-50mg) 4
• Apply cool compresses to affected areas for symptomatic relief 5
• Avoid scratching, which can worsen skin irritation 4

Monitor closely for progression of symptoms over the next 30 minutes to several hours. 3

Essential Medical Evaluation

You must see a physician urgently (same day) for:

• Complete allergologic work-up including skin prick testing and measurement of specific IgE antibodies to confirm insulin allergy 2
• Assessment of diabetes control and immediate alternative insulin strategy 1
• Prescription of an epinephrine auto-injector for future emergency use if continuing any insulin therapy 3

Management Strategy Going Forward

Do not use insulin glargine (Lantus) again until proper allergy testing is completed. 2

Alternative insulin options after allergologic evaluation:

• Switch to a different insulin analog (such as insulin aspart via continuous subcutaneous insulin infusion) if allergy is specific to glargine 1
• Consider insulin desensitization protocol if allergic to multiple insulin types, performed under close supervision by allergist and endocrinologist 2
• In select Type 2 diabetes patients, switching to oral antidiabetic medications may be possible 2

Important caveat: Cross-reactivity between different insulin analogs varies significantly—some patients allergic to insulin glargine tolerate other long-acting insulins like insulin detemir, while others react to multiple formulations 1. This requires individualized testing and cannot be predicted without formal allergologic evaluation.

Critical Pitfalls to Avoid

• Never dismiss generalized itching as a minor local reaction—this represents systemic involvement and can herald more severe reactions with subsequent exposures 2
• Do not attempt to "push through" symptoms or reduce the dose—continued exposure increases sensitization risk 2
• Avoid self-managing without medical supervision—insulin allergy requires coordinated care between diabetologist and allergist 2
• Do not assume all insulins will cause the same reaction—proper testing is essential before trying alternative formulations 1