Final answer:
A patient with conjunctivitis, urethritis, arthritis, and oral lesions likely has Reactive Arthritis. Tests such as HLA-B27, chlamydial NAATs, urinalysis, ESR, and CRP can support the diagnosis. Joint fluid analysis might be warranted to further investigate the arthritis symptoms.
Step-by-step explanation:
The presentation of conjunctivitis, urethritis, arthritis, and oral lesions is characteristic of Reactive Arthritis, formerly known as Reiter's syndrome. This condition is often associated with HLA-B27 and can follow infectious diarrheal or urogenital illnesses, suggesting an infectious etiology.Regarding laboratory tests, the physician may order a HLA-B27 test, given the patient's symptoms align with Reactive Arthritis. Additionally, since chlamydia is a common precipitating infection, tests for chlamydial infection could be included, such as nucleic acid amplification tests (NAATs) from a urethral or cervical swab, or a urine test for Chlamydia DNA. Other investigations might involve urinalysis to check for pyuria, which is an excess of white blood cells in the urine indicating urinary tract infection, and general blood tests to measure inflammation levels (e.g., erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)). Joint fluid analysis may also be warranted if arthritis symptoms are prominent.It's important to note, while the constellation of symptoms is strongly indicative of Reactive Arthritis, definitive diagnosis will often depend upon the result of these tests, along with the exclusion of other similar conditions. Therefore, multiple tests may be required to reach a conclusive diagnosis.