Allergic Contact Cell-Mediated Hypersensitivity in Psoriasis: A Narrative Minireview

Abstract

The dysfunctionality of the protective skin barrier in psoriasis allows easier cutaneous penetration of various contact haptens; thus, such patients can develop allergic contact hypersensitivity as a comorbidity. Both skin conditions involve T-cell-mediated mechanisms. Dermatologists and allergists should consider assessing allergic contact cell-mediated hypersensitivity in selected psoriasis patients, especially those with palmoplantar psoriasis and who are refractory to topical treatments, and in patients with psoriasis, with or without arthritis, treated with biologics that present skin lesions clinically suggestive of contact dermatitis.

Prevalence and trends of contact sensitization in patients with psoriasis in Lithuania

“… 14 Histological assessments of psoriasis samples reveal epidermal hyperplasia with elongated rete ridges, parakeratosis associated with focal orthokeratosis, and the presence of neutrophil (Munro) abscesses, as well as a disappearance of the granular layer of the epidermis and T-cell infiltrate. 1 These findings align with the results of in vivo and in vitro experiments, which show that keratinocytes in psoriasis patients are less susceptible to apoptosis. 15 , 16 On the other hand, ACD is a type IVa hypersensitivity reaction, characterized by 2 distinct phases.…”

“…On one hand, the coexistence of contact sensitization with psoriasis may explain the localization of some lesions, treatment resistance and prognosis with increased skin disease morbidity. 1 Jo et al reported a case of Koebner phenomenon due to allergic contact hypersensitivity and suggested investigating for possible contact sensitization if the pruritic lesions involve pustules and vesicles. 8 However, several epidemiological and cohort studies have reported an inverse relationship between the 2 diseases.…”

“…The hallmark of ACD, apoptotic processes, are in contrast to the apoptosis-resistant and metabolic-active epidermis that is characteristic of psoriasis. 1 Additionally, the migration of antigen-presenting cells into the local lymph node is delayed in patients with psoriasis. 18 A previous study investigating the characteristics of ACD in psoriasis patients reported delayed patch test reactions compared to nonpsoriatic individuals, with the average peak reaction intensity occurring after 7 days in psoriasis patients compared to 3 to 5 days in the control group.…”

“…Allergic contact dermatitis (ACD) and psoriasis are highly prevalent inflammatory skin disorders characterized by epithelial alterations and deviated T cell immunity. 1 Main characteristics of psoriasis are squamous, well-demarcated erythematous plaques of variable size, which are the result of abnormal proliferation and differentiation of keratinocytes and a dysregulation of immune cell activation in the dermis and epidermis. 2 Meanwhile, ACD is mainly distinguished by erythema, papules, and vesicles followed by scaling, resulting from type IV hypersensitivity induced keratinocyte apoptosis.…”

“… 2 Meanwhile, ACD is mainly distinguished by erythema, papules, and vesicles followed by scaling, resulting from type IV hypersensitivity induced keratinocyte apoptosis. 1 , 3 Despite the distinct pathophysiology of these 2 conditions, they can cooccur, with contact allergy being a coexisting condition in psoriasis patients in about 20% to 25% of cases. 4 Contact dermatitis can result in poorer management of psoriasis due to additional epidermal disruption.…”