Between a Rock and a Hard Place: Management of Systemic Lupus Erythematosus and Porphyria Cutanea Tarda

Porphyria cutanea tarda (PCT), the most common porphyria, is a rare photodermatosis characterized by fragile, hemorrhagic bullae and erosions with associated milia, hyperpigmentation, and hypertrichosis. SLE is a systemic connective tissue disease with approximately 80% of those affected manifesting cutaneous findings. These include malar and discoid rashes, photosensitivity, bullae, oral ulcerations, as well as a variety of other non-specific findings. In this case we illustrate a rare but established association between these two pathologic entities, and the resulting therapeutic challenge in treating a patient with both conditions. The concurrence of these two diseases poses therapeutic challenges with a paucity of evidence-based recommendations. Management with low dose weekly antimalarial therapy may be the appropriate middle ground in effectively treating the two co-morbid conditions especially in a patient with other underlying systemic conditions.

Six week evaluation of the potential for topical desoximetasone 0.25% spray to induce photoallergic skin reaction

PURPOSE

Desoximetasone 0.25% topical spray is a novel formulation that has not been tested or approved for safety and efficacy. The primary objective was to determine the potential of desoximetasone 0.25 and 0.05% topical sprays, as well as a vehicle to induce photoallergic skin reaction after repeated topical application and irradiation to the skin using a controlled photopatch testing procedure.

MATERIALS AND METHODS

53 subjects completed the study, each with six application sites (two of each treatment), three of which were irradiated and three non-irradiated, for an induction period of three weeks and then challenge period at week 6.

RESULTS

Desoximetasone 0.25 and 0.05%, as well as vehicle showed no evidence of potential to induce photosensitization. There was statistically significantly greater irritation at the vehicle irradiated site in comparison to the irradiated treatment area of desoximetasone 0.25% (p = .005) and the irradiated treatment area of desoximetasone 0.05% (p = .008).

CONCLUSION

Our results suggest that regular treatment with desoximetasone 0.25 and 0.05% spray, followed by UV light exposure does not induce photosensitization or photo-irritation. These findings increase confidence for the use of this topical spray in eczema or psoriasis patients who may also be receiving UV light therapy and may contribute to the clinical management of these patients.

4-Day evaluation of the irritation potential of topical desoximetasone 0.25% and 0.05% spray on light-exposed skin

PURPOSE

The safety and potential side effects of desoximetasone 0.25% and 0.05% sprays have not previously been studied. The primary objective of this study was to determine the irritation potential of desoximetasone 0.25%, 0.05% and vehicle sprays in response to irradiation.

MATERIALS AND METHODS

Thirty-four subjects were enrolled in the study, each with three study treatments (desoximetasone 0.25%, 0.05% topical sprays and vehicle) were applied to two sites each on the back of every subject, with half of the sites irradiated with filtered UV light. Dermal reactions at the test sites were evaluated using a visual scale with corresponding numerical scores that rated the degree of erythema and oedema.

RESULTS

Desoximetasone 0.25%, 0.05%, and vehicle caused no detectable signs of phototoxicity when examined on days 3 and 4. Mean scores of desoximetasone 0.25%, 0.05% and vehicle to non-irradiated treatment areas showed no signs of irritation.

CONCLUSIONS

Our results suggest that regular application of desoximetasone 0.25% and 0.05% topical sprays do not induce photosensitization or photoirritation. The safety of this topical spray may help with clinical management of patients using topical corticosteroids while also receiving therapeutic UV light exposure. Thus, patients can use desoximetasone sprays without concerns of side effects due to therapeutic light or sun exposure.

Age-related changes in male forearm skin-to-fat tissue dielectric constant at 300 MHz

Prior research suggests that tissue dielectric constant (TDC) values are useful to assess localized skin water in females for early diagnosing breast cancer treatment-related lymphoedema and TDC values in young adults have shown gender differences. However, no TDC data are available for older males nor have ageing effects been studied despite known shifts in water state and other skin age-related changes. Thus our goals were to (i) characterize TDC values at various skin depths in young and older males, (ii) determine the dependence of these values on body composition parameters and (iii) establish inter-arm TDC ratios for use as normal male reference values. TDC measurements were made to depths of 0·5, 1·5, 2·5 and 5·0 mm bilaterally on volar forearm skin in 60 males in three groups of 20 that had mean ages ± SD of 24·0 ± 0·9, 40·0 ± 12·9 and 71·0 ± 8·0 years. Total body fat and water percentages were determined via bioimpedance at 50 KHz. Results showed that (i) for all age groups TDC values decreased with increasing depth, (ii) TDC values were not statistically different among age groups except at a depth of 0·5 mm, (iii) TDC values were highly negatively correlated with total body fat and (iv) inter-arm ratios varied little among age groups and depths. It is concluded that (i) age-related larger TDC values at only the shallowest depth is consistent with skin water shifting state from bound to more mobile in the oldest group and (ii) inter-arm ratios at any depth provide a basis to test for unilateral oedema.

ESR technique for noninvasive way to quantify cyclodextrins effect on cell membranes

A new way to study the action of cyclodextrin was developed to quantify the damage caused on cell membrane and lipid bilayer. The Electron Spin Resonance (ESR) spectroscopy was used to study the action of Randomly methylated-beta-cyclodextrin (Rameb) on living cells (HCT-116). The relative anisotropy observed in ESR spectrum of nitroxide spin probe (5-DSA and cholestane) is directly related to the rotational mobility of the probe, which can be further correlated with the microviscosity. The use of ESR probes clearly shows a close correlation between cholesterol contained in cells and cellular membrane microviscosity. This study also demonstrates the Rameb ability to extract cholesterol and phospholipids in time- and dose-dependent ways. In addition, ESR spectra enabled to establish that cholesterol is extracted from lipid rafts to form stable aggregates. The present work supports that ESR is an easy, reproducible and noninvasive technique to study the effect of cyclodextrins on cell membranes.

Development of a new topical system: drug-in-cyclodextrin-in-deformable liposome

A new delivery system for cutaneous administration combining the advantages of cyclodextrin inclusion complexes and those of deformable liposomes was developed, leading to a new concept: drug-in-cyclodextrin-in-deformable liposomes. Deformable liposomes made of soybean phosphatidylcholine (PC) or dimyristoylphosphatidylcholine (DMPC) and sodium deoxycholate as edge activator were compared to classical non-deformable liposomes. Liposomes were prepared by the film evaporation method. Betamethasone, chosen as the model drug, was encapsulated in the aqueous cavity of liposomes by the use of cyclodextrins. Cyclodextrins allow an increase in the aqueous solubility of betamethasone and thus, the encapsulation efficiency in liposome vesicles. Liposome size, deformability and encapsulation efficiency were calculated. The best results were obtained with deformable liposomes made of PC in comparison with DMPC. The stability of PC vesicles was evaluated by measuring the leakage of encapsulated calcein on the one hand and the leakage of encapsulated betamethasone on the other hand. In vitro diffusion studies were carried out on Franz type diffusion cells through polycarbonate membranes. In comparison with non-deformable liposomes, these new vesicles showed improved encapsulation efficiency, good stability and higher in vitro diffusion percentages of encapsulated drug. They are therefore promising for future use in ex vivo and in vivo experiments.