Serious And Unserious Risks Of Insulin Injection

Many patients develop some blurring of vision soon after
starting insulin, which makes reading difficult. 

This is due to a
change of lens refraction, and it corrects itself within two to
three weeks.

Patients should be advised that this may occur,
both to avoid extreme anxiety which they may experience, and
to stop the needless purchase of new glasses.

Transient oedema
of the feet is not uncommon during the first few weeks of
insulin treatment.
Insulin treatment

Fatty lumps at injection sites are common, and occasionally
so large as to be unsightly. 

Their cause is not known but they
sometimes develop if injections are repeatedly given over a very
limited area of skin. For this reason it is best to vary the site from
day to day.

They are rarely troublesome, but once present they
tend to persist; the occasional very large fatty tumour may even
require surgical removal. 

Furthermore if insulin is repeatedly
injected into a fatty lump, the rate of absorption may be delayed
and this may have some adverse effect on blood glucose control.
 

Fat atrophy at injection sites is now very rare.
 

Red itchy marks at injection sites after starting insulin are
also rare, and if they do occur usually disappear spontaneously.
If they are very troublesome, adding hydrocortisone to the
insulin bottle so that each dose contains about 1 mg eliminates
the problem. 

Insulin allergy causing urticaria still occurs from
time to time though it is certainly a very infrequent event:
investigation by skin testing and desensitisation may be needed.
Abscesses at injection sites are also remarkably rare