T-helper immune phenotype may underlie 'paradoxical' tumour necrosis factor-α inhibitor therapy-related psoriasiform dermatitis.

BACKGROUND: Therapeutics targeting tumour necrosis factor (TNF)-α are effective for psoriasis; however, in patients treated for other disorders, psoriasis may worsen and psoriasiform dermatitis (PsoD) may arise. T helper (Th) cytokines in psoriasis upregulate keratin (K)17, which modulates TNF-α transduction, leading to vascular adhesion molecule upregulation and lymphocytic extravasation. AIM: We investigated Th phenotype and expression of K17, intercellular adhesion molecule (ICAM)-1 and vascular adhesion molecule (VCAM)-1 in psoriasis and anti-TNF-α-related PsoD. METHODS: Skin biopsies from patients with psoriasis unresponsive to TNF-α inhibitor therapy (n = 11), PsoD-related to TNF-α inhibition (n = 9), untreated psoriasis (n = 9) or atopic dermatitis (AD; n = 9) were immunohistochemically analysed for Th1, Th2, Th17 and Th22. Expression of K17, ICAM-1 and VCAM-1 was also examined. RESULTS: Anti-TNF-α-unresponsive psoriasis and anti-TNF-α-related PsoD showed decreased Th1 : Th2 raio and increased Th17 : Th1 ratio compared with untreated psoriasis. Anti-TNF-α-unresponsive psoriasis had significantly fewer Th1 (4% vs. 12%) and more Th17 (51% vs. 20%) cells than untreated psoriasis. No difference in Th22 cells was identified. K17 was present in all cases of untreated psoriasis and anti-TNF-α-related PsoD, 91% of anti-TNF-α-unresponsive psoriasis, and only 22% of AD. VCAM-1 and ICAM-1 in anti-TNF-α-related PsoD was akin to untreated psoriasis, but decreased in anti-TNF-α-unresponsive psoriasis. CONCLUSIONS: These findings further the current understanding of the anti-TNF-α-related psoriasiform phenotype and support a rationale for therapeutic targeting of interleukin-17 and TNF-α in combination.

Delayed type IV hypersensitivity reaction to porcine acellular dermal matrix masquerading as infection resulting in multiple debridements.

INTRODUCTION: Delayed type IV hypersensitivity reactions are well established in the surgical setting with respect to external exposure via topical antibiotics and internal exposure via synthetic materials. In contrast, biologic matrix is derived from decellularized human or animal tissues and is consequently believed to elicit a minimal host inflammatory response. OBJECTIVE: We report a case of delayed type IV hypersensitivity reaction secondary to a biologic comprised of porcine-derived acellular dermal matrix, [Strattice™]. CONCLUSIONS: While biologic matrix is often preferred over synthetic mesh due to its decreased risk for infection, this case emphasizes that potential for hypersensitivity to the material persists. Type IV hypersensitivity reactions should be included in the differential diagnosis for suspected post-operative infections.

Case report. Appearance of nephrogenic fibrosing dermopathy on a bone scan.

We report a case of nephrogenic systemic fibrosis involving the thighs bilaterally in a patient who received multiple MRI scans with gadolinium. A recent bone scan demonstrated uptake of radiotracer in a region that correlates with CT and dermatopathological findings.