I had awful adult acne, hideous cystic lumps that left scars. My college pictures are hard to look at. This continued into late twenties. It was [due to] a food allergy [that] took forever to figure out: black tea. Especially Oolong. [Oolong and black tea are usually distinguished. Black tea is "fully-fermented", oolong "semi-fermented". -- Seth] My face would begin to itch within minutes of drinking, and the breakout came the following day. But it took years to notice the connection. . . . Green tea is no problem. Coffee is no problem.
In response to my questions, he verified the connection:
On Tuesday night, I drank two cups of strong black tea. Itching began within a hour, and mouth sores hit 18 hours later. Now at 48 hours, very slight acne breakout, but not bad at all.
Part of figuring out the problem was realizing that face itching was a bad sign. The black tea –> itching connection was relatively easy to notice. Another difficulty was the wrong ideas he’d been taught:
To figure out the tea, I first had to unlearn things that turned out to be wrong. Unlearning seems to be much slower than learning.
First, when I was in high school, acne was widely considered to be partly a hygiene problem. So I spent vast useless effort washing several times a day, while possibly missing signals that the cause was something else. Later, in college, I tried washing my face only with water, and then not at all. This turned out to have no effect on acne. That was the first clue of wrong learning.
Second, in high school I drank a lot of grapefruit juice. The citric acid was extremely painful on the mouth sores. I somehow concluded, maybe just emotionally biased by the sharp pain, that grapefruit juice was causing the sores. In college I didn’t drink grapefruit juice, but there was no effect on mouth sores.
Third, a received wisdom was that acne is hormonal, and there was not much you could do but try to manage it. So I didn’t even try to look for an environmental cause, until I was still suffering from acne well into my twenties.
These three wrong conclusions probably cost me years.
Not to mention the astonishing claim of dermatologists that acne is not caused by diet. This list of what to do about acne from the American Academy of Dermatology says nothing about food. It is plausible that in this situation — in 2014, after hundreds of years of experience treating the problem and thousands of medical journal articles about it — the overall effect of doctors is to make things worse.