Occupational and environmental acne is a dermatological disorder associated with industrial exposure. Polyhalogenated hydrocarbons, coal tar and products, petrol, and other physical, chemical, and environmental agents are suggested to play a role in the etiology of occupational acne. The people working in the field of machine, chemistry, and electrical industry are at high risk. The various occupational acne includes chloracne, coal tar, and oil acne. The most common type in clinic is the comedones, and it is also seen as papule, pustule, and cystic lesions. Histopathological examination shows epidermal hyperplasia, while follicular and sebaceous glands are replaced by keratinized epidermal cells. Topical or oral retinoic acids and oral antibiotics could be used in treatment. The improvement in working conditions, taking preventive measures, and education of the workers could eliminate occupational acne as a problem.
Part of the book: Acne and Acneiform Eruptions
Sudden changes in immune-mediated response to Mycobacterium leprae antigen are referred to as leprosy reactions. The reactions manifest as acute inflammatory episodes rather than chronic infectious course. There are mainly two types of leprosy reactions. Type 1 reaction is associated with cellular immunity and particularly with the reaction of T helper 1 (Th1) cells to mycobacterial antigens. This reaction involves exacerbation of old lesions leading to the erythematous appearance. Type 2 reaction or erythema nodosum leprosum (ENL) is associated with humoral immunity. It is characterized by systemic symptoms along with new erythematous subcutaneous nodules.
Part of the book: Hansen's Disease