Schiller test: what it is, how it is done and results

The Schiller test is a diagnostic test that consists of applying a solution with iodine, Lugol, to the internal region of the vagina and cervix and aims to check the integrity of the cells in this region.

When the solution reacts with the cells present in the vagina and cervix and turns brown, the result is said to be normal, however, when it fails to color a specific area, it is a sign that there is a change, making it necessary to perform more specific exams.

Normally, the Schiller test is performed during colposcopy and is therefore recommended for women who are sexually active or who have had altered results in the preventive test, the Pap smear.

When is indicated

The Schiller test is recommended by the gynecologist for sexually active women as a routine exam, for those who present any symptoms such as pain, discharge or bleeding after sexual intercourse or who have had altered results in the Pap smear, also known as a preventive exam.

Furthermore, the doctor may request the examination when there is a suspicion of a gynecological disease, such as HPV, syphilis, vaginal inflammation or cervical cancer. In these cases, in addition to carrying out the Schiller test, it may be necessary to carry out additional tests, such as biopsy, transvaginal ultrasound and colposcopy, for example. Find out more about the tests that may be requested by the gynecologist.

Make an appointment with your nearest gynecologist to check whether you need to take the Schiller test:

How is done

The Schiller test is performed during a Pap smear or colposcopy, with the doctor applying an iodine solution to the cervix. Lugol is applied using a swab, which is a swab with cotton at the tip, and is lightly tapped on the spot to stain the area. After about a minute, the doctor evaluates the cervix to check the presence or absence of changes.

What does the result mean

According to observation of the cervix after Lugol placement, the Schiller test can be positive or negative:

Positive Schiller test

The Schiller test is positive when, after placing the Lugol, not all of the Lugol is absorbed by the tissue, and yellowish areas can be seen on the cervix, which indicates that there are changes in the cells, which may suggest the presence of benign or malignant changes. , as:

• Improperly placed IUD;
• Vaginal inflammations;
• Syphilis;
• HPV infection
• Cervical cancer.

However, the Schiller test can give a false positive result, which is why the Pap smear is generally requested instead, as a means of investigating cervical cancer, as it provides clearer and more concrete results. Furthermore, to confirm the positivity of the Schiller test and identify the cause of the change, the doctor may request a biopsy to visualize characteristics of the tissue and cells.

Another test similar to this is the acetic acid test, which uses the same coloring principle for the vagina and cervix, in which case the region should be whitish. In places where white is more evident, there are signs of cellular changes. This test is particularly recommended for women who are allergic to iodine and, therefore, cannot take the Schiller test.

Negative Schiller test

The Schiller test is said to be negative when after staining with Lugol, the entire vaginal mucosa and the cervix were stained, with no yellowish regions being observed, which indicates that there are no changes in the woman’s genital region, that is, it is normal.