Scalp pruritus is a frequent problem encountered in dermatological practice. This disorder is caused by various underlying diseases and is a diagnostic and therapeutic challenge. Scalp pruritus may be localized to the scalp or extended to other body areas. It is sometimes not only associated with skin diseases or specific skin changes, but also associated with lesions secondary to rubbing or scratching. Moreover, scalp pruritus may be difficult to diagnose and manage and may have a great impact on the quality of life of patients. It can be classified as dermatologic, neuropathic, systemic, and psychogenic scalp pruritus based on the potential underlying disease. A thorough evaluation of patients presenting with scalp pruritus is important. Taking history and performing physical examination and further investigations are essential for diagnosis. Therapeutic strategy comprises removal of the aggravating factors and appropriate treatment of the underlying condition. All treatments should be performed considering an individual approach. This review article focuses on the understanding of the pathophysiology and the diagnostic and therapeutic management of scalp pruritus.

Background: Intravascular B-cell lymphoma (IVBCL) is a rare type of extranodal lymphoma in which the lymphoma proliferates within vascular lumen. One of the most common presenting symptoms is prolonged fever. Although examination of a random skin biopsy from healthy-appearing skin in patients with suspected intravascular lymphoma has been reported to be useful, the sensitivity of this method for diagnosis is still unknown. Objective: To evaluate the usefulness of a random skin biopsy in the diagnosis of intravascular lymphoma in the patient presenting with fever of unknown origin. Materials and Methods: All cases that we performed random skin biopsy were retrospectively reviewed from March 2007 to June 2012 in Ramathibodi Hospital. The incisional biopsy technique was performed in 3 separate locations including 2 specimens from both upper thighs and 1 specimen from the abdomen. Results: Of the 24 cases that were consulted to dermatologist for random skin biopsy, 3 cases (13%) were diagnosed of intravascular lymphoma and all presented with prolong fever, weight loss, and remarkable deterioration in Eastern Cooperative Oncology Group (ECOG) performance status (ECOG score) > 2. Interestingly, 2 cases (8%) were diagnosed with cytophagic histiocytic panniculitis from normal-appearing skin and subsequently investigated, which leads to the diagnosed of T-cell lymphoma. Conclusions: In an elderly patient with fever of unknown origin and/or weight loss with no evident of skin lesion, markedly elevated lactate dehydrogenase, remarkable deterioration in ECOG performance status who suspected IVBCL should be consider to perform incisional random skin biopsy at least 3 specimens from both thighs and abdomen to achieve a high sensitivity. We propose that this technique may serve as an important diagnostic tool to obtain the diagnosis of IVBCL. In summary, 5 of 24 (21%) positive results from random skin biopsy helped diagnoses of lymphoma.

En coup de sabre is a rare subtype of linear morphea, located on the forehead or frontoparietal scalp. Systemic treatment of localised morphea with methotrexate has been reported in a few clinical reports. However, there are no case series using methotrexate treatment for En coup de sabre. To evaluate the efficacy and tolerability of methotrexate in the treatment of en coup de sabre linear morphea subtype. A retrospective chart review was performed for paediatric and the adult patients with en coup de sabre evaluated in the Dermatology Clinic at Wake Forest University School of Medicine treated with methotrexate. There were 7 patients who met criteria for inclusion in the study. The mean age at the onset of disease was 11.8 years (ranging from 4 to 38 years). The mean duration of disease before receiving methotrexate therapy was 9.4 months (ranging from 3 to 24 months). Seven (100%) patients improved with methotrexate therapy, in an average of 2 months to disease inactivity, and 16 months to discontinuation of methotrexate. Methotrexate appeared to be an effective and safe therapy for en coup de sabre patients.

Background: The use of methotrexate-acitretin (MTX-ACI) combination therapy in treating psoriasis has been limited due to concerns related to hepatic fibrosis. However, in vitro evidence revealed a protective effect of acitretin in methotrexate (MTX)-induced liver fibrosis. Objective: This study aimed to compare the real-life incidence of hepatic fibrosis in patients with psoriasis receiving MTX-ACI and MTX monotherapy and to investigate factors associated with hepatic fibrosis in MTX-exposed patients. Methods: A retrospective cohort study was conducted based on a real-life registry containing data on patients with psoriasis who were administered MTX-ACI or MTX between 2008 and 2019 and underwent transient elastography according to cumulative MTX dose of 1.0– 1.5 g and/or 3.5– 4.0 g. Time-to-event analysis was performed to determine the cumulative incidence, incidence rate, and factors potentially affecting the occurrence of hepatic fibrosis. Results: Of the 160 patients, 32 (20%) were treated with MTX-ACI, and 128 (80%) with MTX alone. Four patients (12.5%) in MTX-ACI group and 21 (16.4%) in MTX group developed hepatic fibrosis (p = 0.59). There was no statistically significant difference in cumulative incidence (16% in MTX-ACI vs 17% in MTX, p = 0.89) and incidence rate (37 cases per 1000 person-year in MTX-ACI vs 23 cases per 1000 person-year in MTX; hazard ratio [HR] = 1.07; p = 0.90) of hepatic fibrosis between the two groups. Diabetes and obesity were identified as significant factors associated with hepatic fibrosis (adjusted HR = 2.40, 95% confidence interval [CI]: 1.05– 5.51; p = 0.04 and adjusted HR = 3.28, 95% CI: 1.18– 9.16; p = 0.02, respectively) regardless of the cumulative MTX dose. Conclusion: The incidence of hepatic fibrosis in a real-life clinical situation, determined by transient elastography in patients with psoriasis receiving MTX-ACI, was not increased compared to those receiving MTX monotherapy. Type 2 diabetes mellitus and obesity were identified as risk factors of hepatic fibrosis; hence, patients with these factors receiving long-term MTX therapy should be regularly monitored for this particular event.

Objective: To report an overview of dermatologic adverse events (AEs) related to biologics used for psoriasis and compare common dermatologic AEs across different biologic classes. Data Sources: A comprehensive search in MEDLINE via PubMed from inception through June 9, 2021, was conducted. Study Selections: The selection process was performed independently by two reviewers. Studies were eligible if patients were diagnosed with plaque-type psoriasis, were treated with biologics, and had >= 1 dermatologic AE. Results: A total of 1023 records were identified, and 127 studies were included. The incidence of dermatologic AEs was 4.17% for tumor necrosis factor-alpha (TNF-alpha) inhibitors, 9.49% for interleukin (IL)-12/23 inhibitor, 12.40% for IL-17 inhibitors, and 7.37% for IL-23 inhibitors. Biologic-related dermatological AEs can be classified into allergic skin reactions, inflammatory skin diseases, skin infections, skin neoplasms, and miscellaneous AEs. An evident class effect was observed. Skin neoplasms (1.45%), mainly nonmelanoma skin cancer (1.36%), predominated among TNF-alpha inhibitors. Allergic skin reactions (6.25%) were frequently reported with IL-12/23 inhibitor. During treatment with IL-17 inhibitors, skin infections (5.01%) were common, and the most common was driven by mucocutaneous candidiasis (4.85%). Inflammatory skin disease (2.32%), mainly eczematous eruptions (0.84%), dominated in IL-23 inhibitors. Conclusions: A predominance of specific dermatologic AEs appears in distinct biologic classes due to their different specific targets of action. Further study is needed to understand the mechanisms of these potential AEs, which will help in their management.