NUR 555 Module 9 Final Project Example

Final Project: Joints, Rash and Fatigue in a 26-Year-Old, Separating Systemic Lupus Erythematosus From Its Mimics

[Student Name]

Southern New Hampshire University

NUR 555: Advanced Clinical Pathophysiology

Final Project

[Instructor Name]

[Date]

The organization, setting and figures below are a composite written as a model document. No real employer, client, colleague or patient is described.

Final Project: Joints, Rash and Fatigue in a 26-Year-Old, Separating Systemic Lupus Erythematosus From Its Mimics

Systemic lupus erythematosus is sometimes called a great imitator, because its early features overlap with several other conditions. This final project applies the discrimination practiced across the course to one composite patient whose joints, skin, mouth and energy are all affected. It presents the case, builds a ranked differential, explains the immunology of lupus and tests each alternative against the findings. The analysis concludes that lupus is by far the best explanation, because the combination of a photosensitive malar rash, nonerosive arthritis, leukopenia, anti-double-stranded DNA antibodies and low complement reflects immune complex disease driven by loss of tolerance to nuclear antigens, a pattern that rheumatoid arthritis, parvovirus infection and drug-induced lupus each fail to reproduce in full.

The Case

The patient, a 26-year-old woman who works as a preschool teacher, has had three months of fatigue and pain with swelling in the knuckles and wrists of both hands, worse in the morning. After a weekend outdoors, a flat red rash spread over both cheeks and the nasal bridge, leaving the folds running from nose to mouth clear. She has painless ulcers on the roof of her mouth and evening temperatures up to 38.3°C. She takes no regular medicines. Examination confirms swelling of several knuckles and both wrists and the facial rash.

Laboratory results: white cell count 3,200/mm³, hemoglobin 11.4 g/dL, platelets 140,000/mm³; antinuclear antibody (ANA) positive at 1:640; anti-double-stranded DNA (anti-dsDNA) antibodies positive; C3 and C4 both low; rheumatoid factor weakly positive, anti-CCP negative; urine protein-to-creatinine ratio 0.3 g/g; C-reactive protein mildly raised. Hand x-rays show soft tissue swelling without erosions. Parvovirus B19 IgM is negative.

The Differential

Four diagnoses fit parts of the picture. Systemic lupus erythematosus fits the multisystem pattern. Rheumatoid arthritis fits the symmetric small-joint arthritis and morning stiffness. Parvovirus B19 infection fits a young adult who works with small children and has acute symmetric arthritis and sometimes a rash and transient autoantibodies (Kerr, 2016). Drug-induced lupus fits lupus-like features after exposure to certain medicines. The task is to decide which explains all the findings and which explain only some.

The Immunology of Lupus

Lupus begins with loss of tolerance to the cell's own nuclear material. Impaired clearance of cells that die by apoptosis leaves nuclear antigens such as DNA and histones exposed; plasmacytoid dendritic cells sense these complexes and produce type I interferons, which activate other immune cells and sustain autoreactive B cells. The B cells produce antibodies against nuclear antigens, including anti-dsDNA, which form immune complexes with their targets (Kiriakidou & Ching, 2020). Deposited in tissues, these complexes activate complement and recruit inflammatory cells, a type III hypersensitivity process.

Each finding follows. Ultraviolet light increases apoptosis of skin cells, releasing nuclear antigens where complexes form, which explains why the malar rash appeared after sun exposure. Immune complex inflammation in the synovium causes arthritis, typically without erosions. Complement consumed in forming and clearing complexes explains the low C3 and C4, and antibodies against white cells, together with interferon effects, explain the leukopenia. Fever and fatigue reflect systemic inflammation driven by interferons and other cytokines.

Testing the Mimics

Rheumatoid arthritis explains the arthritis and even the weakly positive rheumatoid factor, which occurs in some people with lupus. But it does not explain the photosensitive malar rash, oral ulcers, leukopenia, anti-dsDNA or low complement. Anti-CCP, highly specific for rheumatoid arthritis, is negative, and there are no erosions after three months (Smolen et al., 2016). Rheumatoid arthritis is unlikely.

Parvovirus B19 infection can cause acute symmetric arthritis in adults, particularly in those exposed to young children, and it can transiently produce autoantibodies and low complement, mimicking lupus (Kerr, 2016). Her occupation makes this a genuine concern. But her negative parvovirus IgM argues against recent infection, and the three-month course, anti-dsDNA and mucocutaneous features favor lupus. Drug-induced lupus usually follows months of exposure to medicines such as hydralazine or procainamide, commonly lacks anti-dsDNA and rarely lowers complement; she takes no medicines, so it can be set aside.

Applying the Classification Criteria

The 2019 EULAR/ACR criteria require a positive ANA at 1:80 or higher as an entry criterion, then add weighted points from clinical and immunologic domains, counting only the highest-weighted item in each domain; a total of 10 or more classifies lupus (Aringer et al., 2019). Table 1 applies them to this patient.

Table 1

2019 EULAR/ACR Classification Criteria Applied to the Case

Note. Only the highest-weighted criterion in each domain is counted. Composite case.

Her total of 27 far exceeds the threshold. Classification criteria are designed for research and are not a substitute for clinical judgment, but here they agree with the analysis: every domain points in the same direction, and no competing diagnosis accounts for the full pattern.

What the Diagnosis Demands

Lupus can affect the kidneys silently, so her urine protein-to-creatinine ratio of 0.3 g/g, below the level counted in the criteria, still needs repeat testing along with blood pressure and urine sediment, since lupus nephritis often begins without symptoms. Hydroxychloroquine is recommended for most people with lupus because it reduces flares and improves long-term outcomes, and baseline and periodic eye examinations are needed while taking it (Kiriakidou & Ching, 2020). She should use sun protection, since ultraviolet light triggered her rash, and her antiphospholipid antibody status should be checked because it affects clotting and pregnancy risk. Referral to rheumatology is appropriate for confirmation and ongoing care.

Conclusion

This patient's joints, skin, mouth, blood and complement all tell the same immunologic story: loss of tolerance to nuclear antigens, interferon-driven autoimmunity and immune complexes that consume complement and inflame tissues. Rheumatoid arthritis explains the joints but not the rest, parvovirus infection could mimic the picture but is unsupported by serology and course, and drug-induced lupus lacks a drug. The 2019 criteria confirm what the mechanism predicts. The course's central skill, asking what each finding means for each possibility, turned a list of symptoms into a diagnosis.

References

Aringer, M., Costenbader, K., Daikh, D., Brinks, R., Mosca, M., Ramsey-Goldman, R., Smolen, J. S., Wofsy, D., Boumpas, D. T., Kamen, D. L., Jayne, D., Cervera, R., Costedoat-Chalumeau, N., Diamond, B., Gladman, D. D., Hahn, B., Hiepe, F., Jacobsen, S., Khanna, D., . . . Johnson, S. R. (2019). 2019 European League Against Rheumatism/American College of Rheumatology classification criteria for systemic lupus erythematosus. Arthritis & Rheumatology, 71(9), 1400-1412. https://doi.org/10.1002/art.40930

Kerr, J. R. (2016). The role of parvovirus B19 in the pathogenesis of autoimmunity and autoimmune disease. Journal of Clinical Pathology, 69(4), 279-291. https://doi.org/10.1136/jclinpath-2015-203455

Kiriakidou, M., & Ching, C. L. (2020). Systemic lupus erythematosus. Annals of Internal Medicine, 172(11), ITC81-ITC96. https://doi.org/10.7326/AITC202006020

Smolen, J. S., Aletaha, D., & McInnes, I. B. (2016). Rheumatoid arthritis. The Lancet, 388(10055), 2023-2038. https://doi.org/10.1016/S0140-6736(16)30173-8