Although working with mineral  oil can predispose to acne,84 oil acne is now very uncommon. Investigations have shown that oil acne may result  from  insoluble cutting  oils causing mechanical obstruction  of the pilosebaceous duct. Only occasionally do frank inflammatory lesions arise, these being in the form of papules and pustules;  furunculosis and  scarring may result. This type of acne can occur as early as six weeks after exposure and commonly affects those areas of the skin in contact with  the oil,  in particular  the thighs  and lower arms. In the past thirty years, oil acne has been seen much less frequently in the dermatolgy clinics, as a result of an improvement in working conditions.

Crude petroleum in oilfield  and refinery works and vegetable oils used as cosmetics in India are  known to be comedogenic. Fiddler's neck   is  a  condition affecting violin  and viola players.  Although  well  known to musicians, it is not well-recognized by dermatologists. Clinically, the lesions usually consist of a localized area of lichenification on the neck - just below the angle of the jaw. Pigmentation, erythema and inflammatory papules, or  pustules,  are frequently present  but nodules, cysts and scarring occur much less often. The aetiology of the  skin changes is probably due to  a combination of factors - friction giving rise to lichenification, while local pressure, shearing stress and occlusion may play a part in producing the acne-like changes. Treatment with retinoic acid may help.