**5. Case**

A 37-year-old man suffered from AD since the age of 3 months. Most part of his childhood he spent in hospitals due to exacerbations of AD. The treatment included pharmacotherapy and physiotherapy treatment. Usually, hospital courses were accompanied by subsequent spa courses. No seasonality was noted. In adulthood, the patient worked as a software developer, but the exacerbations of atopic dermatitis continued to be frequent. For the past 3 years the micro-reaction of precipitation with plasma and in activated serum and inactivated serum was false-positive, no clinical signs of syphilis were revealed, and treponemal tests (reaction of passive hemagglutination, immunoenzyme analysis for treponema pallidum) were negative. Earlier the patient had passed some childhood infections, and acute respiratory viral infections. The patient denied syphilitic infection in anamnesis. And no medical documentation with any mention of syphilis was presented.

The past 2 weeks' acute inflammation on the skin is noted. The patient suffered from severe itching and insomnia. The face, scalp, neck, trunk, and upper and lower extremities are involved. The skin is dry. The periorbital zone presented moderate swelling and rugosity. The mouth angles are infiltrated (**Figure 1**). The elbow bands and popliteal spaces are lichenificated (**Figure 2**). Polymorphous eruptions with infiltrated erythema, excoriations, and superficial erosions with irregular borders were located on the scalp, neck, trunk, and extremities. Dermographism is persistent white.

The results of blood analysis were within normal limits, except the erythrocyte sedimentation rate, which was 43.

The analysis of AIDS and hepatitis was negative.

The micro-reaction of precipitation with plasma and in activated serum and inactivated serum was negative both with capillary and venous blood. The reaction of passive hemagglutination, immunoenzyme analysis for treponema pallidum) were negative.

So, the patient with severe AD had typical false-positive tests for syphilis, when the nontreponemal test was positive and treponemal tests were negative.

*False-Positive Serologic Reactions for Syphilis DOI: http://dx.doi.org/10.5772/intechopen.106370*

**Figure 1.** *Lesions on the face.*

**Figure 2.** *Lesions in popliteal areas.*
