A Case Report of Generalized Pustular Psoriasis Associated With IgA Nephropathy

Abstract

Psoriasis vulgaris is a complex immune-mediated disorder that manifests as a chronic skin disorder, characterized by well-circumscribed inflammatory, erythematous plaques. In this case report, we present a patient with generalized pustular psoriasis (GPP) who presented to the nephrology department with rapidly progressive decline in renal function. The diagnosis of GPP was made a month ago, secondary to a coagulase-negative staphylococcal superinfection. Intrinsically, this introduced a diagnostic challenge as the presumed diagnosis of immunoglobulin A (IgA) nephropathy had to be distinguished from IgA-dominant infection-related glomerulonephritis. We further discuss the current evidence and immunohistological profiles of IgA nephropathy in psoriasis and detail the evolution of renal function of our patient over 25 months after he presented to our department.

Keywords: glomerulonephritis; iga nephropathy; nephritic; nephrotic; psoriasis; psoriatic nephropathy.

Figure 1. Hand examination showing hyperkeratotic, psoriasiform scaling of digits 2 and 3 on the left hand (arrow) and onychodystrophy of the first digits bilaterally (arrow).

Figure 2. Histologic examination showing a crescent (asterisks) and mesangial hypercellularity with matrix expansion (arrow).

Figure 3. Immunofluorescence showing more intense staining for IgA (A) rather than C3 (B) and larger, more globular staining of lamba (C) than kappa (D) light chains.

Figure 4. Electron microscopy in image A showing a large electron-dense paramesangial deposit (arrow), without formation of subepithelial humps (thus ruling out post-streptococcal glomerulonephritis) and in image B effacement of podocytes (asterisks) and more electron-dense subendothelial deposits (arrow).

Figure 5. Evolution of the patient's renal function and corresponding treatments over 25 months after initial admission to our department with acute kidney injury.

GFR: glomerular filtration rate; Cr: creatinine; RBC: red blood cell.

Figure 6. The figure shows our differential diagnoses and reasons for excluding them.

IgAN: immunoglobulin A nephropathy; IgA-IRGN: immunoglobulin A-dominant infection-related glomerulonephritis; cANCA: antineutrophil cytoplasmic antibody; pANCA: perinuclear antineutrophil cytoplasmic antibody.