Home > E. Pathology by systems > Skin > psoriasis
psoriasis
Friday 14 November 2003
cutaneous psoriasis
Images
neutrophils in stratum corneum in psoriasis, vs. pustule of Kogoj in stratum spinosum
Synopsis
The biopsy shows psoriasis, based on these findings: 1) parakeratosis with 2) an absent granular layer, 3) acanthosis (hyperplasia / overgrowth of the epidermis) most prominent at the rete ridges, 4) dermal chronic inflammation and prominent capillaries.
Another common finding is 5) neutrophils in the parakeratotic epidermis - called Munro microabscesses. The patient frequently has a scaly, silver rash.
A major clue to psoriasis is parakeratosis with an ABSENT GRANULAR LAYER. Other findings include prominent rete ridges, prominent dermal capillaries and inflammation, and Munro microabscesses - neutrophils in the parakeratotic epidermis.
epidermal anomalies in psoriais
ungueal anomalies in psoriasis
NAIL INVOLVEMENT:
seen in up to 50% of psoriasis patients, more common in patients with psoriatic arthropathy
histopath -> psoriasiform onychitis with spongiform pustulation, negative fungal special stains (see photos)
differential -> onychomycosis, eczematous onychitis, Reiter syndrome
Susceptibility loci
PSORS1 locus at 6p21 (12148091)
IL12B variants (17236132)
IL23R variants (17236132)
Reviews
Schon MP, Boehncke WH. Psoriasis. N Engl J Med. 2005 May 5;352(18):1899-912. PMID: 15872205
Gottlieb AB. Psoriasis: emerging therapeutic strategies. Nat Rev Drug Discov. 2005 Jan;4(1):19-34. PMID: 15688070
Bowcock AM, Cookson WO. The genetics of psoriasis, psoriatic arthritis and atopic dermatitis. Hum Mol Genet. 2004 Apr 1;13 Spec No 1:R43-55. PMID: 14996755
Bhalerao J, Bowcock AM. The genetics of psoriasis: a complex disorder of the skin and immune system. Hum Mol Genet. 1998;7(10):1537-45. PMID: 9735374
References
Cargill M, Schrodi SJ, Chang M, Garcia VE, Brandon R, Callis KP, Matsunami N, Ardlie KG, Civello D, Catanese JJ, Leong DU, Panko JM, McAllister LB, Hansen CB, Papenfuss J, Prescott SM, White TJ, Leppert MF, Krueger GG, Begovich AB. A large-scale genetic association study confirms IL12B and leads to the identification of IL23R as psoriasis-risk genes. Am J Hum Genet. 2007 Feb;80(2):273-90. PMID: 17236132
