Use more than 30 spf sunscreen three times a day. Regarding neck darkening, are you overweight? Any family history of similar problem?. It may be acanthosis nigricans. You may need topical de pigmenting cream & if required chemical peels by dermatologist
Next Steps
show to nearby qualified dermatologist.
Answered2018-05-10 14:24:41
Let others know if this answer was helpful