Christopher M. Baker

Chronic actinic dermatitis: A retrospective analysis of 44 cases referred to an Australian photobiology clinic

A retrospective study was performed to analyse the clinical and photobiological features and therapeutic outcomes of 44 patients with chronic actinic dermatitis who were evaluated over an 8.3‐year period. The study population comprised 37 men and seven women with a mean age of 62.7 years (range 26–85 years). The most common abnormal phototest results were decreased minimal erythema doses to both UVA and ‐B (73.8%), and to UVA alone (14.3%). Twenty‐six patients (78.8%) had at least one allergic, photoallergic or combined allergic/photoallergic reaction. A total of 139 positive contact or photocontact reactions were recorded (mean 4.2 per patient). Most commonly, treatment consisted of photoprotection, topical corticosteroids and episodic use of systemic agents, in particular azathioprine.

RESEARCH REPORT Bexarotene capsules and gel for previously treated patients with cutaneous T‐cell lymphoma: Results of the Australian patients treated on phase II trials

Bexarotene (Targretin®, LGD1069) is a novel synthetic retinoid analogue that binds selectively to retinoid X receptors. We describe eight previously treated patients who entered phase II international multicentre studies examining the role of bexarotene in cutaneous T‐cell lymphoma. Patients received either the oral formulation (n = 7) or the topical gel (n = 1). Of the seven patients who received 300 mg/m2per day capsules, five (71%) achieved a partial response, with mean time to onset of response of 27 days (range, 20–29) with responses persisting for a mean of 92 days (range, 57–115). The single patient receiving the topical preparation (stage IB) remains in partial response at 31 months. The major toxicity with oral administration was hypertriglyceridaemia requiring therapy. Bexarotene capsules and gel are active and generally well‐tolerated agents in patients with cutaneous T‐cell lymphoma and studies examining its role in previously untreated patients or as part of combination therapy are warranted.

Actinic prurigo: a retrospective analysis of 21 cases referred to an Australian photobiology clinic.

Actinic prurigo (AP) is a rare acquired idiopathic photodermatosis, reported most often in American Indians, but also in Caucasian and Asian populations. The skin lesions in AP predominantly affect exposed sites but may involve covered areas, and often result in postinflammatory scarring. The diagnosis of AP can be difficult and relies on a combination of history, clinical experience and investigations including phototesting and human leucocyte antigen typing. Twenty‐one patients (17 women, four men) diagnosed with AP at the photobiology clinic at St Vincent’s Hospital Melbourne were reviewed in this retrospective study. The mean age of patients at presentation to the clinic was 25 years, with the mean age of onset being 14 years. Phototesting was undertaken in 20 patients, with 12 (60%) having reduced and eight (40%) normal minimal erythema doses. Human leucocyte antigen typing indicated 18 patients (85.7%) were DR4 positive, with further subtyping of the DR4 allele establishing that 15 patients (71.4%) were DRB1*0407 positive and that two (9.5%) were DRB1*0401 positive. This condition is often recalcitrant, with treatment options including photoprotection, topical and oral corticosteroids, antimalarials, phototherapy and thalidomide.

Refractory subacute cutaneous lupus erythematosus successfully treated with rituximab

A 48‐year‐old woman presented with pruritic, scaly, annular plaques over her upper back and chest that were clinically, serologically and histologically characteristic of subacute cutaneous lupus erythematosus (SCLE). She failed to respond to conventional treatment, which included high‐dose hydroxychloroquine, methotrexate, prednisolone, chloroquine, acitretin, thalidomide, dapsone and azathioprine. Subsequently treated with intravenous rituximab 375 mg/m2 weekly for 4 weeks, she remained on adjuvant oral hydrochloroquine 600 mg daily and topical clobetasol propionate 0.05% ointment as required. Clearing of annular plaques was noted 8 weeks after the initial course of rituximab. By 12 weeks there were no new lesions and only post‐inflammatory hyperpigmentation remained. Both hyper‐ and hypopigmentation, which is more common, are consistent with SCLE lesion regression. Skin lesions recurred 11 months later; however, no further lesions occurred after re‐introduction of rituximab therapy. The treatment was well tolerated. A maintenance regimen of rituximab, 375 mg/m2 every 8 weeks for 2 years, was commenced 3 months after completing the second course of treatment, with ongoing disease remission. Rituximab appears to have activity in refractory SCLE and clinical trials are required to further assess this potential therapy.

Management of the primary cutaneous lymphomas

Cutaneous lymphomas are rare and, although some are a manifestation of systemic lymphoma, the majority arise primarily from the skin. These primary cutaneous lymphomas comprise both T‐ and B‐cell subtypes and represent a wide spectrum of disorders, which at times can be difficult to diagnose and classify. Classical therapeutic strategies include topical corticosteroids, phototherapy, radiotherapy, retinoids, extracorporeal photopheresis, topical chemotherapy, systemic chemotherapy and biological response modifiers. Newer therapies include the synthetic retinoid bexarotene, the immunotoxin conjugate denileukin diftitox, interleukin‐12 and monoclonal antibodies such as alemtuzumab and rituximab.

Eradicating down the food chain: optimal multispecies eradication schedules for a commonly encountered invaded island ecosystem

Free to read at publishers site. Islands are global hotspots of both biodiversity and extinction. Invasive species are a primary threat, and the majority of islands have been invaded by more than one. Multispecies eradications are essential for conserving the biodiversity of these islands, but experience has shown that eradicating species at the wrong time can be disastrous for endemic species. Managers not only have to decide how to eradicate each invasive species, they need to determine when to target each species, and how to control multiple species with a limited budget. We use dynamic control theory to show that, when resources are limited, species should be eradicated in a particular order (an eradication schedule). We focus on a common invaded island ecosystem motif, where one invasive predator consumes two prey species (one endemic, one invasive), and managers wish to eradicate both invasives while ensuring the persistence of the endemic species. We identify the optimal eradication schedule for this entire class of problem. To illustrate the application of our solution, we also analyse a particular case study from Californias Channel Islands. For any island ecosystem that shares this motif, managers should begin by allocating all of their resources towards invasive predator control. Only later should resources be shifted towards controlling the invasive prey. This shift should ideally be gradual, but an abrupt shift is very close to optimal. The Channel Islands case study confirms these findings. Targeting both species simultaneously is substantially suboptimal. We reach the robust conclusion that the same eradication schedule should be applied to any island with this ecosystem motif, even if the ecosystem contains different species to the Channel Islands case study.Synthesis and applications. Although very numerous, the worlds invaded island ecosystems could be described by a limited range of invaded ecosystem motifs. By calculating robust optimal eradication schedules for each motif, the approach defined in this study could offer rapid decision-support for a large number of future conservation projects where specific data are scarce. Although very numerous, the worlds invaded island ecosystems could be described by a limited range of invaded ecosystem motifs. By calculating robust optimal eradication schedules for each motif, the approach defined in this study could offer rapid decision-support for a large number of future conservation projects where specific data are scarce.

Weight gain and tumour necrosis factor-alpha inhibitors in patients with psoriasis.

To compare the effect of anti‐tumour necrosis factor (TNF)‐α therapies with agents that do not target TNF‐α on bodyweight and body mass index (BMI) in patients with psoriasis.

Psoriasis uncovered – measuring burden of disease impact in a survey of Australians with psoriasis

Internationally, the understanding of psoriasis has advanced in recent years to the point now where it is no longer considered a benign or cosmetic skin condition but a systemic, immune‐mediated disease associated with significant comorbidities and considerable detriment to quality of life. The aim of this study was to gain a better understanding of the physical, psychosocial and medical burden of psoriasis on Australian adults and the impact on health status.

Drug-induced solar urticaria due to tetracycline

Solar urticaria is an uncommon disorder characterized by pruritus, erythema and whealing commencing within minutes of exposure to ultraviolet (UV) and visible light, and generally resolves in a few hours. We describe a 28‐year‐old woman who developed pruritus and erythema 5 min after sun exposure while on tetracycline for treatment of perioral dermatitis. Phototesting elicited urticarial reactions in the UVA, UVB and visible spectra. Repeat phototesting after cessation of tetracycline was negative. This report documents the first case of solar urticaria induced by tetracycline.

Late-onset warfarin necrosis

A 43‐year‐old woman developed tenderness and induration of her thighs and lower abdomen, 56 days after commencing warfarin for aortic and mitral valve replacements. Investigations showed elevated inflammatory markers, mild renal impairment, normal echocardiogram and low protein C and S levels consistent with warfarin therapy. Three weeks later, purpuric areas evolved into large tender haemoserous bullae, which broke down to form ulcers. Histology confirmed the clinical impression of warfarin‐induced skin necrosis with dermal and subcutaneous venular thrombi. Despite cessation of warfarin and commencement of heparin, the lesions progressed. When the patient became febrile, blood cultures grew Pseudomonas aeruginosa, which was treated with intravenous imipenem and vancomycin. Wound swabs grew methycillin‐resistant Staphylococcus aureus and the antibiotics were changed. The patient developed septic shock and, despite intensive care management, her condition deteriorated and she died 9 weeks after the onset of the skin symptoms.