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Because of the ubiquitous nature of dermatophytes and a lack of an adaptive immune response in the nail plate, recurrence and relapse rates associated with superficial fungal infections are high (10%–53%). Cured or improved dermatophytosis patients could become reinfected if exposed to fungal reservoirs, such as an infected shoe, sock, or textile. To prevent this, footwear, sock, and textile sanitization methods can be used. To provide insight into effective sanitization options, the focus of this article is to review footwear, sock, and textile sanitization studies conducted throughout history (1920–2016). Thirty-three studies are covered in this review, encompassing techniques ranging from formaldehyde fumigation and foot powder application, to more modern approaches such as UV light and silver-light irradiation technologies. Older sanitization methods (eg, boiling, use of chlorine and salts) are quite limited in their practicality, as they can result in health complications and ruin shoe integrity. Newer approaches to shoe and sock sanitization, such as ozone application and UV irradiation, have shown very promising results. Further research is still needed with these modern techniques, as knowledge gaps and cost prevent the creation of standardized parameters for successful use. By combining sanitization methods with other preventative measures, protection against reinfection may be enhanced.
Chromoblastomycosis is a cutaneous-subcutaneous fungal infection that is being seen more frequently in patients living in the US. The disease normally occurs in patients living in tropical and subtropical regions, but as the number of immigrants into the US increases, podiatrists must be able to recognize the manifestations of chromoblastomycosis. The most common sight involved is the lower extremity where it easily can be confused with other diseases such as tertiary syphilis, phaeohyphomycosis, and cutaneous tuberculosis, among others. Small lesions should be excised, while antifungal drugs, such as itraconazole, should be used when more tissue is involved.
Foot and nail care specialists spend a great portion of their day using nail drills to reduce nail thickness and smooth foot callouses. This process generates a large amount of dust, some of which is small enough to breathe in and deposit into the deepest regions of the respiratory tract, potentially causing health problems. Foot and nail dust often contain fungi, from both fungally-infected and healthy-looking nails. While the majority of healthy individuals can tolerate inhaled fungi, the immune systems of older, immunocompromised, and allergy-prone individuals often react using the inflammatory TH2 pathway, leading to mucus overproduction, bronchoconstriction, and, in severe cases, lung tissue damage. To protect vulnerable podiatry professionals, wearing a surgical mask, using a water spray suppression system on nail drills, installing air filtration systems, and considering drilling technique can help reduce the exposure to nail dust.
Onychomycosis is a chronic fungal infection of the nail that is recalcitrant to treatment. It is unclear why normally effective antifungal therapy results in low cure rates. Evidence suggests that there may be a plethora of reasons that include the limited immune presence in the nail, reduced circulation, presence of commensal microbes, and fungal influence on immune signaling. Therefore, treatment should be designed to address these possibilities and work synergistically with both the innate and adaptive immune responses.
Most fungal infections primarily occur in immunocompromised patients. We describe a case of osteomyelitis involving the first metatarsal head due to Cryptococcus neoformans in a previously healthy immunocompetent patient. She was treated with surgical debridement combined with antifungal drug therapy for 6 months. At 5-year follow-up, she remained symptom free with full range of motion of the first metatarsophalangeal joint. Fungal osteomyelitis should be considered as a possible cause in osteolytic lesions in the metatarsal bone.
Background: Onychomycosis, or fungal nail infection, is the cause of 50% of onychopathies seen by podiatric physicians. This pathology is accompanied by a negative psychosocial component because of its effect on self-image, which is an essential part of social relations. Conventional pharmacologic treatment based on antifungal agents is lengthy and expensive and has a high abandonment rate and a low cure rate. Therefore, a faster and more efficient solution has been sought using laser treatment. However, studies on the efficacy of this physical method are not conclusive due to the lack of uniformity in the method used to apply the laser and an objective method to measure the results. The aim of this study was to measure the efficacy of laser treatment of onychomycosis by microbiological cure and clinical evolution using the Onychomycosis Severity Index.
Methods: A prospective study with a strictly repetitive protocol of Nd:YAG 1,064-nm laser was applied to 50 participants with onychomycosis in the first toe, following the manufacturer's instructions. The efficacy of the treatment on fungal infection was measured by microbiological culture before and after treatment. The clinical evolution of the nail dystrophy was quantitatively evaluated using the Onychomycosis Severity Index.
Results: The efficacy of Nd:YAG 1,064-nm laser in eliminating fungal infection was 30% (15 participants). However, significant improvement in nail appearance (dystrophy) was observed in 100% of patients (P < .001).
Conclusions: Laser treatment has relatively low efficacy in treating fungal infection but results in an objective improvement in the clinical appearance of the nail in 100% of patients.
The Diagnosis of Onychomycosis in a Geriatric Population
A Study of 450 Cases in South Florida
An investigative study was performed to determine the diagnosis of onychomycosis in a South Florida geriatric population. In this study, 450 cases of suspected onychomycosis involving men and women 65 years of age and older from a private practice office and two nursing home settings were used. Samples were taken from the hallux toenail and sent to a mycology laboratory for fluorescent potassium hydroxide (KOH) preparation and microscopic examination of a fungal culture. Of the 450 cases studied, 46.4% of the patients had a single fungal organism cultured, 30.4% had a mixed fungal infection cultured, and 23.1% had no fungal growth. Saprophytes were found in 59.9% of the 526 total fungal organisms cultured while dermatophytes were found in only 23.8%. The results of this investigation demonstrate that there may be a shift from isolated dermatophyte infection to mixed saprophyte infections in a geriatric population with onychomycosis. (J Am Podiatr Med Assoc 91(9): 456-464, 2001)
Although scanning electron microscope technology has been used for more than 60 years in many fields of medical research, no studies have focused on obtaining high-resolution microscopic images of onychomycosis of the toenail caused by Trichophyton rubrum in a geriatric population. To provide new insight into the intricate structure and behavior of chronic toenail onychomycosis, we produced three-dimensional images of onychomycosis obtained from two geriatric patients with confirmed growth of T rubrum. The photomicrographs illustrate the pervasive integration and penetration of the fungus hyphal elements, underscoring the clinical difficulty of obtaining rapid treatment of fungal infections in the distal and lateral subungual space of the human toenail. Although the scanning electron microscope may not be a practical diagnostic tool for most physicians, it remains invaluable for the researcher to obtain insight into the spatial orientation, behavior, and appearance of onychomycosis. (J Am Podiatr Med Assoc 94(4): 356–362, 2004)
Azole Resistance in Dermatophytes
Prevalence and Mechanism of Action
Azole antifungal agents (eg, fluconazole and itraconazole) have been widely used to treat superficial fungal infections caused by dermatophytes and, unlike the allylamines (such as terbinafine and naftifine), have been associated with resistance development. Although many published manuscripts describe resistance to azoles among yeast and molds, reports describing resistance of dermatophytes are starting to appear. In this review, I discuss the mode of action of azole antifungals and mechanisms underlying their resistance compared with the allylamine class of compounds. Data from published and original studies were compared and summarized, and their clinical implications are discussed. In contrast to the cidal allylamines, static drugs such as azoles permit the occurrence of mutations in enzymes involved in ergosterol biosynthesis, and the ergosterol precursors accumulating as a consequence of azole action are not toxic. Azole antifungals, unlike allylamines, potentiate resistance development in dermatophytes.
