Melasma and Sun Spots After Accutane?

Two factors that greatly affect melasma are hormones and sun exposure.  While it's true that Accutane does make you more sun sensitive, this photosensitivity only lasts a couple of months after finishing the course of Accutane.

Also, melasma on the neck is pretty rare.  However other things like for example a common yeast infection of the skin, Tinea Versicolor, can affect the neck, chest and upper back areas and will also look like brown spreading spots on the skin.  It will also worsen with sun exposure, or in general heat and humidity.

I recommend that you see your dermatologist to determine exactly what is going on with your skin.

Accutane actually improves melasma in many patients. It certainly should not be blamed for melasma one year after discontinuation. As far as the dark spots on your body, I would suggest you be evaluated for post-inflammatory hyperpigmentation from possible contact dermatitis, irritant dermatitis, or eczema.

Almost all of the side effects from Accutane (isotretinoin) are temporary and occur only when taking the medication.  There is no evidence that Accutane would cause melasma.  You would not have been left sun-sensitive after completing Accutane.  Patients who are taking Accutane are usually advised to use sun protection and sunscreens because the medication will temporarily make the outer dead skin cell layer more compact, meaning sunlight will penetrate more easily, but this side effects goes away in just a few days or weeks after stopping the medication.  I would consult with a dermatologist to evaluate these brown spots and provide treatment recommendations.  Many other conditions or rashes could be responsible.  Best of luck!