Oral phosphate binders in the treatment of pseudoxanthoma elasticum.

BACKGROUND: Pseudoxanthoma elasticum (PXE) is a systemic connective tissue disorder involving elastic fiber calcification and fragmentation with major clinical manifestations occurring in the cutaneous, ocular, and cardiovascular systems. Normalization of the serum calcium-phosphate product through hemodialysis in a previous patient with perforating periumbilical PXE and elevated serum phosphate resulted in regression of skin lesions. OBJECTIVE: We sought to study the effect of pharmacologically limiting the intestinal absorption of phosphate in patients with PXE. METHODS: Patients received baseline skin examinations, target skin lesion evaluation, and photography; renal function tests and serum calcium and phosphate levels; urine calcium, phosphate, and creatinine levels; skin biopsy; and eye examinations and indocyanine-green angiography. Patients were treated with aluminium hydroxide tablets or liquid and returned every 2 to 4 months for skin photography and lesion evaluation. Repeated skin biopsies were performed on clinically improved target sites. Ophthalmologic evaluation was obtained at yearly intervals. RESULTS: Of 6 patients, 3 showed significant clinical improvement of skin lesions and all 3 of these patients showed histopathologic regression of disease in their target lesions. No deterioration of eye disease was seen in any of the 6 patients at 1-year follow-up. CONCLUSION: Our results demonstrate that the calcification seen in PXE may be reversible in some patients. This could hold true for eye and vascular lesions and for skin. Further studies supporting these results could reveal the first real treatment option for PXE.

Long-term efficacy and safety of tretinoin emollient cream 0.05% in the treatment of photodamaged facial skin: a two-year, randomized, placebo-controlled trial.

BACKGROUND: Long-term (>1 year) placebo-controlled studies of tretinoin in the treatment of photodamaged skin have not been conducted. Recently, we conducted a 2-year placebo-controlled study of tretinoin emollient cream 0.05%, including histopathologic assessment of safety and analysis of markers of collagen deposition. OBJECTIVE: The objective of the study was to determine the long-term safety and efficacy of tretinoin emollient cream 0.05% in the treatment of moderate to severe facial photodamage. METHODS: A total of 204 subjects were treated with tretinoin or placebo (vehicle emollient cream) applied to the entire face once a day for up to 2 years. Clinical and histologic effects were assessed at regularly scheduled clinic visits. RESULTS: Treatment with tretinoin resulted in significantly greater improvement relative to placebo in clinical signs of photodamage (fine and coarse wrinkling, mottled hyperpigmentation, lentigines, and sallowness), overall photodamage severity, and investigator's global assessment of clinical response (p<0.05). Histologic evaluation showed no increase in keratinocytic or melanocytic atypia, dermal elastosis, or untoward effects on stratum corneum following treatment with tretinoin compared with placebo. Immunohistochemistry studies, conducted at three study centers, showed a significant increase relative to placebo in facial procollagen 1C terminal, a marker for procollagen synthesis, at month 12 (p=0.0074). CONCLUSION: Long-term treatment with tretinoin emollient cream 0.05% is safe and effective in subjects with moderate to severe facial photodamage.

Clinical effect of imiquimod 5% cream in the treatment of actinic keratosis.

BACKGROUND: Actinic keratosis (AK) is the earliest clinical manifestation of squamous cell carcinoma. Metastatic SCC causes the majority of the 1300 to 2300 deaths attributed to nonmelanoma skin cancer in the United States each year. Recent studies have shown that intralesional administration of interferon can be used successfully in the treatment of AK. OBJECTIVE: Imiquimod is an immune response modifier, currently approved for the treatment of genital warts. The topically applied immune response modifier acts by up-regulating interferon and other cytokines involved in the cell-mediated immune response at the site of application. The aim of this was to determine the efficacy and safety of imiquimod 5% cream for the treatment of AK. METHODS: Twenty-two patients with AK lesions were treated with imiquimod 5% cream, initially at 3 times per week for 8 weeks, or until total clearance of lesions. Patients applied imiquimod to lesions on one side of the body and vehicle cream to the other side. A total of 17 patients who completed treatment were evaluated for number of lesions and adverse reactions before treatment and at weeks 2, 4, 6, and 8 after initiation of treatment. AK lesions were also assessed 4 and 8 weeks after treatment. RESULTS: A significant reduction in the average number of lesions per patient was observed for patients treated with imiquimod. The most frequent reactions to treatment were erythema, itching, and scabbing; however, all adverse events were mild to moderate. CONCLUSION: Imiquimod 5% cream may be a promising treatment for AK.

6-thioguanine in the treatment of psoriasis: a case report and literature review.

BACKGROUND: 6-Thioguanine is a purine analog primarily indicated for acute myelogenous leukemia. Its use in psoriasis was first investigated in the 1950s and current interest in serious treatments for psoriasis, such as cyclosporine, has renewed interest in this medication. Newer therapies, such as PUVA and retinoids, have side effects as do some older treatments, such as methotrexate, which fell into favor at the same time 6-thioguanine was being investigated. Reexamining older treatments can open up new therapeutic options in difficult cases. OBJECTIVE: The goal of this article is to provide a comprehensive review of the literature regarding the use of 6-thioguanine in the treatment of psoriasis as well as an illustrative case report demonstrating the use and side effects of 6-thioguanine in a patient with pustular psoriasis. Topics reviewed include efficacy, side effects, laboratory monitoring, different dosing regimens, and proposed mechanisms of action. CONCLUSIONS: 6-Thioguanine has been highly effective in treating and maintaining improvement in patients with psoriasis. A study comparing efficacies with methotrexate would be extremely useful. Because of the possibility of severe bone marrow depression, 6-thioguanine is not a first-line treatment. However, with new dosing regimens, proper laboratory monitoring, and further studies, use of 6-Thioguanine could expand in the future.