Christian Gan

Background: Lymphocytic thrombophilic arteritis is a distinctive but poorly understood lymphocytic vasculitis. There is a need to better define this entity. Objective: We conducted a case-series analysis of all patients with a diagnosis of lymphocytic thrombophilic arteritis known to St Vincent’s Hospital Melbourne Dermatology Unit, in Victoria, Australia, a referral centre for cutaneous vasculitis and lymphocytic thrombophilic arteritis, to better characterise the clinicopathological features of this entity. Methods: All patients who met our clinicopathological criteria for this condition were included. Diagnostic clinical features included the presence of widespread blanchable livedo racemosa and/or macular pigmentation. Diagnostic histological features included the presence of a lymphocytic arteritis with fibrin deposition affecting vessels in the deeper dermis and/or upper subcutis. Cases of lymphocytic thrombophilic arteritis were assessed for demographics, comorbidities, clinical features, histopathology, treatments, and clinical response. Results: Thirty-six cases were identified including 26 female and 10 male patients with an average age of onset of 32.7 years. A high proportion of cases with Asian descent was noted (44.4%). Most cases (94.4%) presented with widespread livedo racemosa. Less common manifestations included petechiae (16.7%), macular pigmentation (22.2%), neuropathy (33.3%), and ulceration (33.3%). A significant association was noted between ulceration and superficial dermal vessel involvement on biopsy, similar to livedoid vasculopathy. All cases demonstrated a neutrophil-poor lymphocytic perivascular infiltrate with fibrinoid change in the deeper dermis/upper subcutis. A variety of vessels were affected; 44.4% involved vessels in the superficial dermis as well as the deep dermis/upper subcutis. A discrete concentric fibrin ring (41.7%) was not essential for diagnosis. Treatments targeting vascular fibrin deposition appeared effective for all manifestations other than livedo for which no cases responded. Conclusion: Lymphocytic thrombophilic arteritis has distinctive clinicopathological features and may lie on a spectrum with livedoid vasculopathy. Although livedo racemosa persists, other manifestations respond to antithrombotic treatments.

The Australian Journal of General Practice (AJGP) aims to provide relevant, evidence-based, clearly articulated information to Australian general practitioners (GPs) to assist them in providing the highest quality patient care

This retrospective analysis of Hedgehog inhibitor treatment in 32 patients with Gorlin syndrome, locally advanced and metastatic basal cell carcinoma (BCC) at three tertiary referral centres in Victoria, Australia from April 2017 until 30 June 2024 demonstrated an 84% overall objective response rate (partial and complete response combined). However, 90% of patients experienced adverse effects impacting quality of life. Secondary acquired drug resistance occurred in 77% (10/13) of locally advanced and metastatic BCC patients after a median duration of 13 months. Further work is needed to optimise the neoadjuvant use of Hedgehog inhibitors with radiotherapy or surgery given poor long‐term Hedgehog inhibitor tolerability and to develop strategies to counteract the issue of acquired resistance.

Melasma is a chronic, acquired disorder of focal hypermelanosis that carries significant psychosocial impact and is challenging for both the patient and the treating practitioner to manage in the medium to long term. Multiple treatments have been explored, often in combination given the many aetiological factors involved in its pathogenesis. Therapeutic discoveries to treat melasma are a focal topic in the literature and include a range of modalities, with recent developments including updates on visible light photoprotection, non-hydroquinone depigmenting agents, oral tranexamic acid, chemical peels, and laser and energy-based device therapy for melasma. It is increasingly important yet challenging to remain up-to-date on the arsenal of treatments available for melasma to find an efficacious and well-tolerated option for our patients.

Recent advances in atopic dermatitis (AD) present the condition as a heterogeneous disease of distinct endotypes across ethnic groups. AD in people with skin of colour may appear psoriasiform, lichenoid, scaly or papular, with a violaceous colour and there is a higher prevalence of post-inflammatory dyspigmentation compared with affected individuals of White ethnicity. These differences in clinical presentation may limit the use of AD assessment tools in people with skin of colour, leading to the potential for misdiagnosis and underestimation of severity, particularly in relation to assessment of erythema. Recent targeted therapies for AD have been studied in multiple ethnic groups; however, ethnicity-based subgroup analysis is often not performed. Further research is required to understand whether treatment responses or safety may differ among ethnic groups.

Lymphocytic thrombophilic arteritis and livedoid vasculopathy may both present with livedo racemosa and ulceration. We present 6 cases with features of both conditions, raising the possibility that they are either closely linked or are part of a spectrum of the same condition.

Atopic dermatitis (AD) is a global condition that has a rising prevalence in developing countries such as those within South-east Asia and Latin America. Recent research represents the condition as a heterogeneous disease of distinct endotypes among different ethnic groups. Variation between ethnic groups in physiological measures such as transepidermal water loss, ceramide/+, skin sensitivity, alongside pathological barrier and immune system dysfunction processes, may ultimately lead to the distinct phenotypes seen clinically. AD in patients of White ethnicities is typified by filaggrin dysfunction, more T helper (Th)1 and less Th17 involvement, with less epidermal thickness compared with patients of Black or Asian ethnicities. AD in patients of Black ethnic groups is Th2/Th22-skewed, with robust IgE expression, and less Th1 and Th17 involvement than patients of Asian or White ethnicities. AD across South Asian and East Asian populations is characterized by Th17/Th22 upregulation. Differences also exist in how AD psychosocially has an impact on individuals of different ethnic groups.