Thank you for your kind words! Your kitty appears to have feline acne. Sometimes the cause is plastic allergy (not in your case) and sometimes it's an allergy to something else and that something else is very difficult to figure out. In addition, the chin is one of the areas some cats do not clean as well. Use a warm wet soft cloth and scrub the chin vigorously every day, even if it bleeds a bit. Continue this for several days and see if there is improvement. If it doesn't improve or gets worse, see your vet.
skillful. 1  having or exercising skill: a skillful juggler. 2  showing or involving skill: a skillful display of fancy diving. 3  Obsolete. reasonable; rational.
proficient implies a thorough competence derived from training and practice. proficient in translating foreign languages; adept implies special aptitude as well as proficiency. adept at doing long division; skilled stresses mastery of technique. a skilled surgeon; skillful implies individual dexterity in execution or performance. skillful drivers