Faculty Bibliography

BACKGROUND:Onychomycosis is a common problem seen in clinical practice. Given the differential diagnosis of dystrophic nails, it is helpful to obtain a definitive diagnosis of dermatophyte infection before the initiation of antifungal therapy. Potassium hydroxide (KOH) preparation and fungal culture, which are typically used in the diagnosis of these infections, often yield false-negative results. Recent reports have suggested that nail plate biopsy using periodic acid-Schiff (PAS) (Bx/PAS) stain may be a very sensitive technique for the diagnosis of onychomycosis. OBJECTIVE:The purpose of this study was to compare KOH preparation, culture, Bx/PAS stain, and calcofluor white (CW) stain in the diagnosis of onychomycosis and to determine their sensitivity and specificity. METHODS:We evaluated 105 patients with suspected onychomycosis using 4 diagnostic methods: KOH preparation, culture, Bx/PAS, and CW stain. CW stain binds to cellulose and chitin, and fluoresces when exposed to UV radiation. It is a highly sensitive and specific technique for the detection of dermatophytes. To determine the clinical usefulness and performance characteristics of each test, CW was chosen as the gold standard for statistical analysis. RESULTS:Of the patients, 93 had at least 1 of the 4 diagnostic methods positive for the presence of organisms. The following were calculated for each test: sensitivity; specificity; positive predictive value; and negative predictive value. The sensitivities of each of the techniques were as follows: KOH 80%; Bx/PAS 92%; and culture 59%. Both KOH and Bx/PAS methods were more sensitive than culture (P =.00002). Bx/PAS was also more sensitive than KOH (P =.03). The specificities were as follows: KOH 72%; Bx/PAS 72%; and culture 82%. The positive predictive value calculated for the different techniques were: KOH 88%; Bx/PAS 89.7%; and culture 90%. In terms of negative predictive value, the results were: KOH 58%; Bx/PAS 77%; and culture 43%. CONCLUSION/CONCLUSIONS:Bx/PAS is the most sensitive method for the diagnosis of onychomycosis. It is also superior to the other methods in its negative predictive value. It is indicated if other methods are negative and clinical suspicion is high, and potentially is the single method of choice for the evaluation of onychomycosis.

Although often overlooked, topical antibiotic agents play an important role in dermatology. Their many uses include prophylaxis against cutaneous infections, treatment of minor wounds and infections, and elimination of nasal carriage of Staphylococcus aureus. For these indications, they are advantageous over their systemic counterparts because they deliver a higher concentration of medication directly to the desired area and are less frequently implicated in causing bacterial resistance. The ideal topical antibiotic has a broad spectrum of activity, has persistent antibacterial effects, and has minimal toxicity or incidence of allergy.

Actinic keratoses (AKs) are evolving, malignant cutaneous neoplasms. AKs can be treated with physical or destructive methods and with topical therapies. This article is the first in a 2-part series that will review current topical therapeutic options for AKs. Several topical treatment options offer some significant benefit for the alleviation of these lesions. Therapies include 5-fluorouracil, imiquimod, diclofenac, colchicine, and retinoids. The first part of this review will focus on topical 5-fluorouracil and imiquimod

Actinic keratoses (AKs) are evolving, malignant cutaneous neoplasms. AKs can be treated with physical or destructive methods and by topical therapies. This article is the second in a 2-part series of current topical therapeutic options for AKs and discusses topical diclofenac, colchicine, and retinoids. The first part focused on topical 5-fluorouracil and imiquimod

During the past several years, a new generation of therapies for psoriasis has been in development. These biologic therapies target the activity of T lymphocytes and cytokines responsible for the inflammatory nature of this disease. The first article of this 2-part update reviewed the tumor necrosis factor (TNF) inhibitors, infliximab and etanercept. In this article, we will review 2 therapies that target the T cell, efalizumab and alefacept.

Polymorphic light eruption (PMLE) is the most common photodermatosis. It is typically characterized by nonscarring, pruritic, erythematous papules, plaques, or vesicles on sun-exposed skin that develop 30 minutes to several hours after sun exposure. The eruption may persist for a few hours to as long as 2 weeks. Females are affected two to three times more often than males. PMLE has been reported in all races, but tends to affect fair-skinned individuals with Fitzpatrick skin types I-IV most commonly. The pathogenesis of PMLE has been difficult to define, although it appears to be an immune-mediated delayed-type hypersensitivity reaction. Abnormalities of arachidonic acid metabolism and a possible correlation with lupus are other theories that are reviewed. Treatment options have been explored extensively. While "hardening" or desensitization of the skin through repeated irradiation seems to be the most effective, therapeutic options such as sun avoidance/sun protection, oral carotenoids, and antimalarials are also considered.

Over the last several years, a new generation of therapies for psoriasis has been in development. These biologic therapies target the activity of T lymphocytes and cytokines responsible for the inflammatory nature of this disease. In this review, we present an update on the progress of the four biologic agents in the forefront: infliximab, etanercept, efalizumab, and alefacept. The mechanism of each drug will be reviewed, as well as the most recent efficacy and safety data

With the growing threat of bioterrorism, it has become important for clinicians to recognize the clinical manifestations of diseases spread in this manner. The aim of this article is to provide readers with a complete and detailed understanding of anthrax, with a specific concentration on the cutaneous manifestations and a concentrated review of the treatment and current information known about Bacillus anthracis.