Symptomatic dermographism (factitious urticaria)--passive transfer experiments from human to monkey

Shedding light on dermographism: a narrative review

Dermographism is a common subtype of chronic urticaria. It generally manifests as a linear wheal after scratching or friction, with or without angioedema. The pathophysiology is not clear, but currently, we believe that the stimulation of the skin by mechanical stress leads to the activation of mast cells, which provoke the release of histamine and pro-inflammatory mediators, ultimately forming wheal along the stressed area. The gold standard for diagnosis is a medical history and provocation test or dermatographic test. As one of the subtypes of chronic urticaria, the Urticaria Control Test (UCT), Chronic Urticaria Quality of Life questionnaire (CU-Q2oL), and Dermatology Life Quality Index (DLQI) are also effective tools for evaluating disease control in dermographism patients. In addition to avoiding triggers, nonsedating H1 antihistamines are the first-line medications recommended by EAACI and other guidelines; for those who do not respond to standard doses, the recommended dosage can be increased up to 4 times. When necessary, the off-label use of omalizumab can be considered, and some drugs with potential therapeutic effects are still being explored. However, there is still a lack of biomarkers for predicting disease severity, efficacy, and prognosis. Here, we review what we know about dermographism and some points that need exploration in the future.

New insights into chronic inducible urticaria

PURPOSE OF REVIEW

Chronic inducible urticaria (CIndU) is a group of long-persisting and challenging to manage diseases, characterized by recurrent wheals and angioedema induced by definite triggers. In this review, we address recent findings on CIndU pathogenesis, diagnosis as well as its treatment, and we discuss novel potential targets that may lead to the development of more effective therapies for CIndU patients.

RECENT ADVANCES

Meaningful advances in the understanding of its pathogenesis have been reported in the last decades. Novel CIndU-specific patient-reported outcome measures enable a closer and better evaluation of patients. CIndU is a hard-to-treat disease that highly impairs quality of life (QoL) of affected patients. Provocation tests allow to diagnose CIndU subtypes. The only licensed and recommended treatment for CIndU are second generation non-sedating H1-antihistamines, which lack efficacy in many cases. Omalizumab off-label use has been assessed in all types of CIndU with overall good outcomes. Promising emerging therapies currently assessed in chronic spontaneous urticaria are paving the path for novel treatments for CIndU.

Atopy in chronic urticaria: an important yet overlooked issue

Chronic urticaria (CU) is one of the most common dermatological diseases and has a significant impact on the quality of life of patients. However, the pathogenesis of this disease remains unclear. Autoimmunity in chronic spontaneous urticaria (CSU) has received considerable attention and has been studied previously. Atopy is an important characteristic of CU; however, it has not been fully recognized. Atopy predisposes individuals to immune responses to allergens, leading to type 2 inflammation and immunoglobulin E (IgE) overproduction. Compared with healthy individuals, patients with CU have a higher proportion of atopy, and an atopic background is correlated with the clinical characteristics of CU. The total IgE levels in patients with CU is significantly higher than those in healthy individuals. Although its level is not higher than that in classic allergic diseases, it is closely related to CU. Exogenous allergens, auto-allergens, and specific IgEs, which are closely related to atopy, have been reported, and their roles in CU pathogenesis are also being studied. Local and systemic atopic inflammation is present in patients with CU. This review summarizes the current knowledge regarding atopy and CU, speculating that there are CU subtypes, such as atopic CSU or atopic chronic inducible urticaria (CIndU) and that atopy may be involved in the pathogenesis of CU. These findings provide a new perspective for a comprehensive understanding of the clinical features of CU and further research regarding its pathogenesis.

Chronic Urticaria: Advances in Understanding of the Disease and Clinical Management

Chronic urticaria (CU) is a common skin condition characterized by the recurrence of wheals, with or without angioedema, which lasts for at least 6 weeks. Owing to its pruritus and incurability, this disease adversely affects the patients' physical and mental health and diminishes the quality of life. CU is generally classified into two subtypes based on the relevance of eliciting factors: chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU), the latter of which is further divided into several subtypes. To improve the understanding and clinical management of this highly heterogeneous disorder, the EAACI/GA²LEN/EDF/WAO guideline was developed and published in 2018 based on evidence and expert consensus. The diagnostic and treatment algorithms proposed by the guideline have largely facilitated dermatologists in clinical practice. However, several questions remained unsolved and have been widely investigated in the recent years. First, a better understanding of the association between chronic urticaria and its potential underlying causes or eliciting factors such as autoimmunity, infections, coagulation aberrance, and vitamin D deficiency is warranted. This would lead to updates in the diagnostic and treatment procedures of different subtypes of chronic urticaria. Secondly, treatment for recalcitrant cases, especially those resistant to or intolerant of second-generation antihistamines and (or) omalizumab, calls for novel therapeutic measures or strategies. In the present review, we summarized recent advances in the understanding and management of both CSU and CIndU, with special emphasis on their underlying causes or eliciting factors, pathogenic mechanisms, potential targets for intervention, and advances in treatment strategies.

Management of chronic urticaria in children: a clinical guideline

The aim of this guidance is to provide recommendations to clinicians and other interested parties on chronic urticaria in children. The Italian Society for Pediatrics (SIP), the Italian Society for Allergy and Immunology (SIAIP), the Italian Society for Pediatric dermatology (SIDerP) convened a multidisciplinary panel that prepared clinical guidelines for diagnosis and management of chronic urticaria in childhood. Key questions on epidemiology, natural history, diagnosis, and management were developed. The literature was systematically searched and evaluated, recommendations were rated and algorithms for diagnosis and treatment were developed. The recommendations focus on identification of diseases and comorbidities, strategies to recognize triggering factors, improvement of treatment by individualized care.

Brain-derived neurotrophic factor is increased in serum levels of patients with symptomatic dermographism

Introduction

Symptomatic dermographism (SD) is the most common form of physical urticaria. However, the role of neuroimmune mechanisms in SD is unclear.

Aim

To investigate circulating levels of brain-derived neurotrophic factor (BDNF) in symptomatic dermographism.

Material and methods

Thirty-two patients suffering from SD and 33 healthy subjects were included in the study. Serum BDNF levels were determined by a human enzyme-linked immunoassay (ELISA) kit. The serum C-reactive protein concentration and eosinophil counts in peripheral blood were evaluated.

Results

The BDNF serum levels were detectable in both SD patients and healthy controls. The BDNF serum levels were significantly higher in patients with SD compared with healthy controls (p = 0.004). There was a positive but weak correlation between serum BDNF and CRP levels; it was not statistically significant (r = 0.211, p = 0.255). There was also a positive but weak correlation between serum BDNF and eosinophil counts; it was not statistically significant (r = 0.271, p = 0.141).

Conclusions

The present study shows that BDNF is increased in the serum levels of patients with SD, suggesting a role for BDNF in the pathophysiology of this disorder.

Omalizumab treatment in patients with chronic inducible urticaria: A systematic review of published evidence

BACKGROUND

Omalizumab, a recombinant anti-IgE antibody, effectively treats chronic spontaneous urticaria. Evidence is lacking in patients with chronic inducible urticarias (CIndUs), which are frequently H₁-antihistamine resistant.

OBJECTIVE

From the current published literature, we aimed to determine the strength of evidence for omalizumab efficacy and safety in the treatment of CIndUs.

METHODS

We performed a PubMed search to identify evidence on omalizumab use in the following 9 CIndU subtypes: symptomatic dermographism, cold urticaria, delayed-pressure urticaria, solar urticaria, heat urticaria, vibratory angioedema, cholinergic urticaria, contact urticaria, and aquagenic urticaria.

RESULTS

Forty-three trials, case studies, case reports, and analyses were identified. Our review indicates that omalizumab has substantial benefits in patients with various CIndUs. The evidence is strongest for symptomatic dermographism, cold urticaria, and solar urticaria. Little/no evidence was available on vibratory angioedema and aquagenic and contact urticaria. Our review supports rapid onset of action demonstrated through early symptom control in most cases, sometimes within 24 hours. Many patients gained complete/partial symptom relief and substantially improved quality of life. Adverse events were generally low, with omalizumab being well tolerated by most patients, including children.

CONCLUSIONS

A strong body of evidence supports the use of omalizumab in the treatment of patients with therapy-refractory CIndU. More data from randomized controlled studies are warranted.

Nonhuman primate dermatology: a literature review

In general, veterinary dermatologists do not have extensive clinical experience of nonhuman primate (NHP) dermatoses. The bulk of the published literature does not provide an organized evidence-based approach to the NHP dermatologic case. The veterinary dermatologist is left to extract information from both human and veterinary dermatology, an approach that can be problematic as it forces the clinician to make diagnostic and therapeutic decisions based on two very disparate bodies of literature. A more cohesive approach to NHP dermatology - without relying on assumptions that NHP pathology most commonly behaves similarly to other veterinary and human disease - is required. This review of the dermatology of NHP species includes discussions of primary dermatoses, as well as diseases where dermatologic signs represent a significant secondary component, provides a first step towards encouraging the veterinary community to study and report the dermatologic diseases of nonhuman primates.

Physical urticaria

Physical urticarias are a unique subgroup of chronic urticaria in which patients develop urticaria secondary to environmental stimuli. Common triggers include exercise, temperature changes, cold, heat, pressure, sunlight, vibration, and water. Systemic symptoms have occurred during severe episodes. Physical urticarias are responsible for approximately 20% to 30% of all cases of chronic urticaria. A basic knowledge of these unusual disorders is important for all healthcare providers. This article covers the following types of physical urticarias: dermatographism, cholinergic urticaria, local heat urticaria, exercise-induced anaphylaxis, vibratory angioedema, solar urticaria, and aquagenic urticaria.

Chronic urticaria

Chronic urticaria remains a major problem in terms of etiology, investigation, and management. It is important to identify patients in whom physical urticaria is the principal cause of disability. Once confirmed by appropriate challenge testing, no further investigation is required. Urticarial vasculitis (UV) is a major differential diagnosis of "idiopathic" urticaria (CIU). I perform biopsy of most patients in this category because UV cannot be considered confirmed in the absence of histologic evidence. Patients with confirmed UV need to be thoroughly investigated for paraproteins, lupus erythematosus hepatitis B and C, and inflammatory bowel disease. Of patients with CIU, a few (<5%) prove to have food additive reactivity confirmed by placebo-controlled challenge testing. There is no convincing evidence of the involvement of Helicobacter pylori or parasite infestation as a cause of chronic urticaria, although H pylori could have an indirect role. Recently it has become clear that 27% to 50% of patients with CIU have functional autoantibodies directed against the alpha-chain of the high-affinity IgE receptor or less commonly against IgG. These antibodies, whose involvement has now been independently confirmed in several centers, are identified by autologous serum skin testing and confirmed by histamine release studies or immunoblotting. Their removal (by intravenous Ig or plasmapheresis) or treatment by cyclosporine has proved highly beneficial in severely affected patients. However, the routine treatment of all CIU patients, irrespective of etiology, remains the judicious use of H(1) antihistamines.

The effect of psoralen photochemotherapy (PUVA) on symptomatic dermographism

A controlled trial of 4-weeks oral photochemotherapy (PUVA) on 14 patients with severe symptomatic dermatographism produced a clinically useful reduction in itching in five patients. In four of these patients itching had relapsed to pre-treatment levels within 3 months of finishing the PUVA course. A comparison of the weal and flare responses on exposed and covered (control) skin using a calibrated dermographometer showed no significant change in skin reactivity, even in the patients who experienced symptomatic relief. While PUVA may temporarily reduce itching in some patients with symptomatic dermographism, its use cannot generally be justified for treating this type of physical urticaria.