Genetics, immunology, and pathogenesis
M. Alan Menter, Caitriona Ryan in Psoriasis, 2017
There is some evidence for the role of trauma in skin psoriasis and possibly PsA. The Koebner phenomenon is an uncommon but well-described occurrence in psoriasis wherein skin plaques develop at sites of trauma to nonlesional skin. Trauma or biomechanical stress has been proposed as a potential cause of enthesitis and joint inflammation in PsA, sometimes referred to as “deep Koebner phenomenon.”18 Interestingly, a history of trauma preceding the onset of peripheral arthritis was reported in 8%–9% of patients with newly diagnosed PsA.19,20 Case–control studies have suggested several other potential causative factors, including joint injury, vaccination, recurrent oral ulceration, repetitive heavy lifting, and infections requiring treatment with antibiotics.18,21 In patients with nail dystrophy, repetitive microtrauma has been hypothesized to play a role in the pathogenesis of distal interphalangeal (DIP) joint involvement by eliciting an aberrant immune response that results in persistent inflammation of the adjacent enthesis and synovium (see Figure 13.1).22
Basics of onychopathology
Archana Singal, Shekhar Neema, Piyush Kumar in Nail Disorders, 2019
Pyoderma gangrenosum is a rare neutrophilic dermatosis of unknown etiology. Gastrointestinal, rheumatic, and other diseases are often associated linking it to the group of autoinflammatory disorders.218 It is characterized by progressive cutaneous ulceration that may start with a tiny tender papule or pustule, which rapidly enlarges. Differentiation from an infection is crucial and may sometimes be difficult.219,220 The pathogenesis includes immune complexes mediating neutrophilic vascular lesions. Trauma and Koebner phenomenon may elicit new lesions. Nail involvement was observed in association with cyclosporin A treatment.221,222 The histopathology of pyodermia gangrenosum is nonspecific and requires clinical data. In the beginning, there is an infiltrate mainly composed of neutrophils. This develops into a necrotizing and suppurative lesion with a lymphocytic margin with perivascular and intramural lymphocytes. Around these, cuffs of neutrophils may be seen. Sometimes, a sweet-like aspect is present.
Inflammation in Psoriasis and Psoriatic Arthritis
Siba P. Raychaudhuri, Smriti K. Raychaudhuri, Debasis Bagchi in Psoriasis and Psoriatic Arthritis, 2017
Psoriasis often develops at sites of trauma (called the Koebner phenomenon). Patients with PsA also have a history of preceding trauma more often than those with other inflammatory arthritides, like rheumatoid arthritis. Rubella vaccination, house moving, recurrent oral ulcers, and bone fractures have also been deemed to be risk factors for the development of psoriasis and related arthritides [7]. The recent proposition to classify psoriasis and PsA as MHC-I-opathy further strengthens the case for a causal link to preceding trauma [8]. Smoking, on the other hand, is protective for psoriasis in individuals carrying the human leukocyte antigen (HLA)-C*06 allele [5,9].
An update on cutaneous complications of permanent tattooing
Published in Expert Review of Clinical Immunology, 2019
A wide number of dermatoses can develop on a tattoo (Table 3) [9–13]. Patients with dermatoses prone to Koebner phenomenon are peculiarly at risk including psoriasis [83], vitiligo [84], or lichen planus [85] (Figure 5(b)). Granulomatous reaction to tattoos, whether the reaction is restricted to one color or not, may reveal systemic sarcoidosis (Figure 5(c)) [86]. Granulomatous reaction and sarcoidosis tend to appear mostly, but not exclusively, on black tattoos [86,87](Figure 5(c)). The presence of other cutaneous lesions or extracutaneous granulomas helps in distinguishing sarcoidosis from a hypersensitivity reaction [86]. TAGU (TAttoo Granulomas with Uveitis) is an exclusion diagnosis that encompasses patients who are developing granulomatous tattoo reactions exclusively associated with uveitis but without any formal proof of systemic sarcoidosis [88]. Lastly, granulomatous tattoo reactions associated with targeted therapies and immunotherapies, such as BRAF-MEK, CTLA-4, and PD-1/PD-L1 inhibitors for cancer start to be reported. Reactions are most likely to occur within old black tattoos and may be associated with sarcoidosis or not [89].
Effects of a topical ointment on responses to treatments used for common genital diseases and on quality of life
Published in Cogent Medicine, 2020
Clarence de Belilovsky, Jean-Marc Bohbot
During psoriasis, 33%–63% of women will develop genital psoriasis (Meeuwis et al., 2011). It causes pruritus, pain, burning sensation, and dyspareunia. It typically expresses as flares but may become chronic and impair QoL and sexual health (Ryan et al., 2015). Treatment includes the use of long-term, sequential or intermittent application of moderate to potent TSs. However, these steroids are often not potent enough to induce a complete response, and thus to completely relieve patients from their symptoms (pruritus mainly; Czuczwar et al., 2016). Patients should avoid trigger factors associated with the Koebner phenomenon. Emollient use is recommended during extra-genital psoriasis to reduce treatment-induced irritation and maintain therapeutic results (Paulsen et al., 2005).
HR-pQCT in vivo imaging of periarticular bone changes in chronic inflammatory diseases: Data from acquisition to impact on treatment indications
Published in Modern Rheumatology, 2021
Camille P. Figueiredo, Mariana O. Perez, Lucas Peixoto Sales, Georg Schett, Rosa M. R. Pereira
Moreover, HR-pQCT studies in RA have shown that bone changes are related to autoantibodies and occur very early in the disease course. Kleyer et al. showed that individuals with anti-citrullinated protein antibodies (ACPA), who have not yet developed RA show cortical bone changes characterized by the appearance of so-called cortical micro-channels (CoMiCs) suggesting that initial bone changes precede the onset of clinical RA [65,66]. Pre-disease bone changes have also been described in PsA. Thus, a cross-sectional study on psoriasis patients without any current or past symptoms of PsA showed that bone changes such as small enthesiophytes (Deep Koebner Phenomenon) can be detected in psoriasis patients while being virtually absent in healthy individuals [67].
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