Teen-agers who claim that stress makes them break out are telling the truth: The stress of taking an exam can make pimples worse, researchers reported on Tuesday. And surprisingly, inflammation may be to blame and not greasy skin, said Dr. Gil Yosipovitch, a professor of dermatology at Wake Forest University School of Medicine.
"A lot of our patients mention that when they are stressed, their acne gets worse," Yosipovitch said in a telephone interview.
But which comes first -- the pimples or the stress? Bacteria are often blamed for the inflammation that causes pimples.
Yosipovitch and his colleagues set up a test to find out if stress contributes, too. They recruited 94 students in Singapore, where the climate is stable, to rule out potential weather factors.
The students, with an average age of just under 15, were undergoing an annual exam that determines whether they can go on to university, or must go into a less-rigorous program.
The students completed a questionnaire widely used in stress research, once just before mid-year exams and during the summer break. Dermatologists assessed whether the students' acne worsened.
Exam time clearly made for breakouts, the researchers reported in Acta Derm Venereol, a Swedish medical journal.
Blackheads, whiteheads and pustules are all caused by a waxy substance called sebum that can be overproduced and clog pores. Adolescents are especially prone to breakouts, but studies have shown cleanliness and diet are not important factors.
The students did not have any more blackheads or whiteheads -- which are blocked pores and do not involve inflammation -- but they did have more pustules or pimples which are raised bumps with pus, a finding that suggests that inflammation is to blame, and not sebum production.
Yosipovitch believes the findings may apply to other skin conditions. "A lot of our skin diseases are associated with stress -- eczema, psoriasis, chronic itch," Yosipovitch said.
"The skin, in my opinion, is a mirror to what is going in our minds."