Prurigo nodularis occurs with chronic pruritus and the presence of single to multiple symmetrically distributed, hyperkeratotic, and intensively itching nodules. Diverse dermatologic, systemic, neurologic, or psychiatric conditions can lead to prurigo nodularis. Structural analysis demonstrated a reduced intraepidermal nerve fiber density and increased dermal levels of nerve growth factor and neuropeptides such as substance P and calcitonin gene-related peptide. Novel therapy concepts such as inhibitors at neurokinin-1, opioid receptors, and interleukin-31 receptors have been developed. The mainstays of prurigo nodularis therapy comprise topical steroids, capsaicin, calcineurin inhibitors, phototherapy, and the systemic application of anticonvulsants, μ-opioid receptor antagonists, or immunosuppressants.

Dear Readers, Itching (pruritus) of a wound, scar, or dermatologic disorder can negatively impact a patient's quality of life, resulting in injurious scratching1 or impeded rehabilitation.2 Like pain, itch can cause the su erer to lose sleep and appetite or even consider suicide.3,4 Clinical measures of pruritus have proved reliable and valid in individuals with burn wounds, dermatologic conditions, or urticaria5-7 or resulting scars,2 allowing studies to clarify its impact on human experience and compare the e ects of interventions to reduce itching. This Evidence Corner explores the e ects on pruritus of interventions applied at 2 very different stages of wound healing: the rst during early healing stages after hemorrhoidectomy8 and the other in postburn hypertrophic scarring with contracture.9 Each condition generates distressing levels of pruritus from which patients eagerly seek relief.

Atopic Dermatitis (AD) is a common chronic inflammatory skin disorder with a constellation of symptoms. Currently, there are numerous therapies in various phases of drug development that target the pathogenesis of AD. Areas covered: Our paper aims to examine small molecule therapies and other novel agents registered for clinical trial in the phase II and mainly phase III stages of development. A literature search using PubMed as well as Clinicaltrials.gov was conducted. Clinical trial evidence of these novel agents was compiled and assessed. Both topical and oral novel therapies with diverse range of mechanistic action are currently being studied, with varying success. These include phosphodiesterase-4 inhibitors, boron molecules, Janus kinase inhibitors, cannabinoid receptors agonists, kappa-opioid receptor agonists. A variety of compounds with yet undisclosed or unknown mechanisms of action are also being studied. Expert opinion: Further research through extensive clinical trials will allow for more information about these targeted therapies and their potential place in the treatment algorithm of AD. Due to the success of such therapies in treating a spectrum of chronic inflammatory diseases, we remain hopeful that the successful development of targeted therapy for AD lies ahead.

Wells syndrome (WS) or eosinophilic cellulitis is a rare, idiopathic, inflammatory dermatosis. The typical clinical presentation is urticarial plaque without preferential location that usually heals without scarring. We present a 62-year-old man with history of lung cancer that had undergone a right superior lobectomy 12 months previously. The patient had a relapsing dermatosis beginning about 6 months before the diagnosis of the lung cancer, characterised by pruritic, erythematous plaques located on the trunk and arms. These lesions spontaneously resolved within a few weeks without scarring. A skin biopsy revealed findings compatible with WS. Several diseases have been associated with WS. These include haematological diseases, fungal, parasitic and viral infections, drug reactions and rarely non-haematological malignancies. We present a case of this rare syndrome in a patient with history of lung cancer that we believe acted as a triggering event. To our knowledge, this is the second case reporting this association.

Belonging to the Trombiculidae family of mites, chigger specifically refers to the larval stage of the mite's life cycle when it is able to bite its host. Although humans act as an accidental host, chiggers will latch on to the skin and their feeding process leads to localized inflammation and irritation. In most cases, these pruritic erythematous papules and papulovesicles are self-healing within a couple weeks, so only symptomatic relief is required as necessary by means of topical antipruritics, oral antihistamines, topical corticosteroids, or an intralesional triamcinolone acetonide injection in severe instances. The best practice, however, is to take preventative measures by completely covering one's skin and applying products containing DEET to the skin and clothing when traveling in infested areas.

Scalp pruritus is a frequent symptom and can be caused by dermatologic diseases, contact allergies, neurologic, psychiatric/somatoform and systemic diseases. In daily clinical practice scalp pruritus is a diagnostic and therapeutic challenge, especially if no detectable lesions are present. A detailed patient history and the inspection of scalp and the skin of the whole body are essential for diagnosis. Depending on the clinical findings, further dermatological diagnostic tests, laboratory analysis, imaging techniques and, where necessary, an interdisciplinary specific diagnostic check-up should be performed. Therapy comprises the treatment of the underlying disease, symptomatic antipruritic treatments such as topical treatment and if applicable systemic treatment. All this should be performed considering the individual situation especially the patient's hair growth and density.

Pruritus can be one of the distressing symptoms of many dermatologic, systemic, neurologic or psychiatric disorders. In each case, the origin of itch is in the skin and/or the nervous system. Involvement of the nervous system causes neurogenic, psychogenic or neuropathic itch. Itch sensation is transferred to the central nervous system via unmyelinated C-type nerve fibers, and many mediators and receptors engage in the its induction and transmission. Also it has been demonstrated that there are similarities and interactions between neurotransmitters and pathways of pain and itch sensation. Hence, effective drugs in reducing the neuropathic pain such as pregabalin have been studied and used in the management of different itchy conditions.  In this narrative review we considered the available published papers dealing with the antipruritic effects of pregabalin. Results of studies conducted in uremic patients show that pregabalin is an effective option in reducing uremic pruritus especially in those who have not responded to antihistamines and topical moisturizers. Data about the effects of pregabalin on other itchy conditions are very limited; however results of the available studies show beneficial effects of this drug in burn patients with more than 5% involvement of the total body surface area, in prurigo nodularis, and in chronic and idiopathic itch. One considerable issue is that the therapeutic effects of pregabalin on uremic pruritus and post burn itch may appear more rapidly than its effects in the other conditions (1-2 weeks vs > 4 weeks). The most reported adverse effects of pregabalin are sedation, dizziness and drowsiness. Whether pregablin can be unequivocally considered as an effective and reasonable choice in the management of pruritus with different causes is a question that should be answered through large scale randomized controlled studies.