An 18-year-old man has facial and upper back lesions that have waxed and waned for the past 6 years. On physical examination, there are 0.3- to 0.9-cm comedones, erythematous papules, nodules, and pustules most numerous on the lower face and posterior upper trunk. Other family members have been affected by this condition at a similar age. The lesions worsen during a 5-day cruise to the Adriatic. Which of the following organisms is most likely to play a key role in the pathogenesis of these lesions?
Teenagers and young adults are affected by acne vulgaris more often than other age groups, and males are affected more often than females. Propionibacterium acnes organisms break down sebaceous gland oils to produce irritative fatty acids, and this may promote the process. The food on the cruise probably did not play a role, but stress causes the lesions to worsen. Staphylococcus aureus and group A streptococci are implicated in the inflammatory skin condition known as impetigo, which can include pustules and a characteristic pale yellow-brown crust. Herpes simplex virus produces vesicular skin eruptions, most often in a perioral or genital distribution. Mycobacterium leprae causes leprosy, which is a chronic condition that can produce focal depigmentation and areas of skin anesthesia.
Group A b-hemolytic streptococcus
Herpes simplex virus type 1
Mycobacterium leprae
Propionibacterium acnes
Skin