**4. Own research**

Since January 2014 till December 2021, we examined nine patients with falsepositive serologic tests for syphilis, aged 48—79. They had no medical documentation with any mentioning of syphilis was presented. They denied syphilitic infection in the past. Three patients were diagnosed with breast cancer, three patients were diagnosed with ovarian cancer, two patients were diagnosed with lupus erythematosus, and one patient was diagnosed with liver cancer.

A 79-year-old patient with liver cancer suffered from diabetes mellitus and obesity as well. The patient denied syphilitic infection in anamnesis. No clinical signs of syphilis were revealed. He was examined thoroughly, and four times during examination and before the operation the micro-reaction of precipitation with plasma and in activated serum and inactivated serum was false-positive, treponemal tests (reaction of passive hemagglutination, immunoenzyme analysis for treponema pallidum) were negative.

A 49-year-old patient suffering from chronic cholecystitis, a 50-year-old patient suffering from thyroiditis, 51-year-old patient suffering from diabetes mellitus showed false-positive serologic reactions for syphilis during the examination and

before the operation for breast cancer showed false- positive micro-reaction of precipitation with plasma and in activated serum and inactivated serum was revealed in these cases, treponemal tests (reaction of passive hemagglutination, immunoenzyme analysis for treponema pallidum) were negative.

A 48-year-old patient, 50-year-old patient, 51-year-old patient had no concomitant diseases, and only after revealing ovarian cancer false-positive micro-reaction of precipitation with plasma and in activated serum and inactivated serum was revealed in these cases, treponemal tests (reaction of passive hemagglutination, immunoenzyme analysis for treponema pallidum) were negative. Repeated studies did not show any changes in serologic reactions.

A 49- and 60-year-old patients with chronic lupus erythematosus showed falsepositive reactions for syphilis since their first diagnosis of lupus erythematosus, accordingly 20 and 37 years ago.

As a result of our search, we proved that different clinical situations (cancer, lupus erythematosus) were accompanied by false-positive tests for syphilis, but we did not find any mention of false-positive test in atopic dermatitis (AD). Meanwhile, the disease is not rare in different countries [85–92]. Now, we present the case.
