Based on the information available, there is no evidence to suggest that consuming skim milk while taking Lipitor (atorvastatin), a medication used to treat high cholesterol, causes any harmful side effects.

Lipitor works by reducing the amount of cholesterol produced by the liver and helping the body remove cholesterol that's already in the blood. Skim milk, on the other hand, is a low-fat dairy product that is often recommended as part of a heart-healthy diet.

While it's always possible for individuals to have unique adverse reactions to specific food-drug combinations, there are currently no widely recognized interactions between Lipitor and skim milk. However, it's always best to consult with a healthcare provider or pharmacist for personalized advice regarding medication use and dietary considerations.

Sources:
1. <https://www.drugs.com/drug-interactions/atorvastatin-with-food,atorvastatin.html>
2. <https://www.webmd.com/cholesterol-management/lipitor-atorvastatin>
3. <https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/cholesterol/art-20045196>
4. <https://www.drugpatentwatch.com/drugs/lipitor>