Benzoyl Peroxide and Sunscreen in Acne-Prone Patients

Botulinum Toxin for Postherpetic Neuralgia

Botox works great for postherpetic neuralgia on the face and scalp, sometimes at surprisingly low doses (such as approximately 1 unit/ cm2); however, in my extensive experience, it does not work at all—ever—on the trunk.

Kevin C. Smith, MD
Niagara Falls, Ontario, Canada

Useful Blood Work Timing With Isotretinoin

When starting patients on isotretinoin, have them start on a low dose for the first 2 weeks (for example, 40 mg/day) before going to the full dose for the next 2 weeks (for example, 80 mg/day). That way, they will be on the full dose of the medication at the first return visit and the labs drawn (liver function tests and triglycerides) will be reflective of the full dose’s effect. If the low dose is taken for the entire month before increasing to the full dose, then labs may have to be repeated to make sure the higher dose is not causing a problem.

Steven R. Feldman, MD, PhD
Winston-Salem, NC

Avoiding Acne While Using Sunscreen

I am fair skinned with a history of multiple basal cell and squamous cell carcinomas. Sunscreens are obligatory. Even as a teen, I never had acne. However, each summer with daily sunscreen use, I have developed a few comedones and the occasional acne papule on my oily forehead and nose. This year, I began to use benzoyl peroxide 5% every morning before the sunscreen, and often at night. I have remained comedone, milia, and papule free.

Robert Richards, MD
Toronto, Ontario, Canada