Annually reassess CGM sensor site health and care

STEP 1 — Gather Information

Collect: visual inspection of current and recent CGM sites for erythema, induration, infection, lipohypertrophy, or tape reaction; patient-reported site comfort and any itching/pain; history of site rotation frequency and locations used; hygiene practices (skin cleaning, drying, adhesive removal); ability to perform SMBG calibrations and use trend data for insulin adjustments; alarm settings and any alarm fatigue.

STEP 2 — Rule In / Rule Out

Is there any abnormal skin finding (redness >2 cm, induration, ulceration, infection, lipohypertrophy, or persistent tape irritation) at the CGM site?

• Yes → proceed to Step 3 (needs intervention).
• No → proceed to Step 3 (site appears healthy).

STEP 3 — Classify or Stratify

Classify site health:

• Healthy – no skin changes, good rotation, proper hygiene.
• Needs reinforcement – mild erythema or irritation resolving, suboptimal rotation, or inconsistent hygiene/calibration.
• Needs intervention – moderate/severe skin reaction, infection, lipohypertrophy, or persistent pain requiring site change.

STEP 4 — Decide

• Healthy: reinforce current site rotation and hygiene plan; continue CGM use with routine SMBG calibration.
• Needs reinforcement: provide brief education on proper skin preparation, rotation (e.g., rotate at least 2 cm from prior site, avoid scar tissue), and hygiene; verify SMBG calibration technique.
• Needs intervention: treat any skin issue per standard care, discontinue use of affected site, select a new insertion site, and educate on prevention before resuming CGM.

Clinical Guardrails / Mimics / Pitfalls

Do not ignore subtle skin changes; do not reuse the same site repeatedly; do not skip SMBG calibrations assuming CGM is sufficient; do not dismiss alarm fatigue without reassessing alert thresholds; do not overlook lipohypertrophy from insulin infusion when assessing CGM sites.

Concrete Clinical Example

A 34‑year‑old with type 1 diabetes presents for annual review. Inspection of the abdomen CGM site shows a 1.5 cm area of mild erythema without induration or drainage. The patient reports rotating sites every 10–14 days but admits to sometimes reusing favorite spots. Skin is cleaned with alcohol wipes before insertion. Decision: erythema classified as needing reinforcement; educate on rotating at least 2 cm from prior site, using antiperspirant‑free skin prep, and avoiding areas of lipohypertrophy; continue CGM with same sensor after site change to adjacent healthy area.

Source: Diabetes Technology—Continuous Subcutaneous Infusion Therapy and Continuous Glucose Monitoring in Adults: An Endocrine Society Clinical Practice Guideline, Endocrine Society, 2016, DOI:10.1210/jc.2016-2534