Better Than the Washing Test — “Diagnosing” Detergent-Reactive Eczema


Now here’s a word I never thought I would use in mixed company:  PATHOGNOMONIC

“Pathognomonic: A sign or symptom that is so characteristic of a disease that it can be used to make a diagnosis. For example, Koplik spots in the mouth opposite the first and second upper molars are pathognomonic of measles.”

Although I must always warn that 1) I am not a doctor, and 2) these are my ideas and not yet established by scientific study, I am ready to go out on a limb with this usage of the above hopefully correctly-spelled word:

I believe now that a persistently clear diaper area — when disposable diapers are used — for a child who otherwise has generalized eczema, is PATHOGNOMONIC of detergent-reactive eczema.

(It pays to be familiar with why the washing test is helpful for understanding the site information and future prevention, and the washing test does have its uses, but it can also have a lot of false negatives, so to speak.)

Now, it’s possible that the problem could be detergent-reactive eczema yet the diaper area not be entirely clear, such as with diaper rash or yeast-infected rash, so having a rash in the diaper area doesn’t necessary rule out detergent-reactive eczema.  However, having a CLEAR diaper area when disposable diapers are used, despite generalized eczema, is pathognomonic for detergent-reactive eczema.

Although this is probably no surprise to readers — it makes sense given the basis for the eczema — I wasn’t willing to, well, go out on a limb until I knew more.  And, until there is a scientific study or studies, I am open to finding out that I am wrong.  But I don’t think so.

Hopefully that insight is helpful to new users and doctors who refer patients to the website.