Overall Prevalence and Prevalence Compared among Psoriasis Treatments of Onychomycosis in Patients with Nail Psoriasis and Fungal Involvement.

BACKGROUND: Whether nail psoriasis can increase the risk of onychomycosis is still being debated, and data relating to the prevalence of onychomycosis among psoriasis patients receiving different treatments is limited. OBJECTIVES: To investigate the overall prevalence and prevalence compared among psoriasis treatments of onychomycosis in patients with nail psoriasis and fungal involvement. METHODS: A prospective study of three groups of nail psoriasis being treated with only topical medication, methotrexate, or biologics (25 patients per group, 150 nails) was conducted at Siriraj Hospital (Bangkok, Thailand) during November 2018 to September 2020. Demographic data, psoriasis severity, and nail psoriasis severity were recorded. The nail most severely affected with psoriasis on each hand was selected for mycological testing. Potassium hydroxide, periodic acid-Schiff stain, and fungal culture were performed. RESULTS: The prevalence of onychomycosis in nail psoriasis was 35.3%. Among the treatment groups, the prevalence of onychomycosis was significantly higher in the methotrexate group than in the topical treatment and biologic treatment groups (p = 0.014). Candida spp. was the main causative organism, followed by Trichophyton rubrum. Thumb was most commonly affected (59.3%). The most common abnormality of the nail matrix and the nail bed was pitted nail (71.3%) and onycholysis (91.3%), respectively. Multivariate analysis revealed diabetes, wet-work exposure, and methotrexate treatment to be predictors of onychomycosis. CONCLUSIONS: Several factors, including psoriasis treatment, were shown to increase the risk of onychomycosis in nail psoriasis. Further research is needed to determine whether biologic agents, especially interleukin-17 inhibitors, can increase risk of onychomycosis and Candida infection/colonization of the nails.

Onychomycosis, the Active Invasion of a Normal Nail Unit by a Dermatophytic Versus the Colonization of an Existing Abnormal Nail Unit by Environmental Fungus.

Onychomycosis was described by early investigators as the presence of an abnormal nail unit and a member of the order Mycota, producing the abnormality. This interpretation has caused more than 50 years of confusion in the dermatologic literature. Unquestionably, the clinician sees more abnormal toenails than fingernails, and investigators have described a multitude of fungi as the cause of the clinically abnormal toenail. In 2010, developmental scientists proved, what we have long recognized, that there is no bilateral symmetry in living organisms and, therefore, one sole is different from the other. This causes a gait asymmetry, coupled with the pressure the closed shoe exerts on toenails while walking. This produces a series of abnormalities, which are clinically identical to what has been described for dermatophytic onychomycosis. These are fungus free and result in toenail niches. These toenail abnormalities were recently described as the asymmetric gait nail unit syndrome (AGNUS). It is possible that environmental fungi can colonize these toenail niches and, therefore, were described by investigators as a new onychomycosis entity In the normal host, onychomycosis should be only used to describe the active invasion of the nail bed (NB) corneocytes by a dermatophyte, as seen in dermatophytic onychomycosis. Dermatophytes only affect those hosts who have inherited the dermatophytosis susceptibility gene, transmitted as an autosomal dominant trait. In studies encompassing 3,000 abnormal toenails, only 27%-30% were found as dermatophyte culture positive, 25% were negative and the rest environmental fungi were recovered.

[Late onset dermatophytic disease]. / Maladie dermatophytique de revelation tardive.

Dermatophytic disease, described for the first time in 1959 by Hadida and Schousboe, is a chronic dermatophyte infection of the skin and viscera. It is a rare disease occurring mainly in Maghreb. Immunological studies have highlighted a deficit of cellular immunity with autosomal recessive transmission responsible for tolerance to dermatophyte. The first signs of this disease usually occur during childhood. Our patient suffered from pachyonychia affecting all his nails and erythematous, circinate, pruritic, scaly lesions occurring in all his seed coat from the age of 50 years. These disorders were gradually followed by alopecia and hair removal of all body hairy areas, palmoplantar keratoderma as well as bilateral axillary and inguinal adenopathies. Tricophyton violaceum was isolated from patient's nails. No immune deficiency was found or visceral involvement within the limits of the assessments made. The evolution was marked by transient improvements, resistance of adenopathies and skin appendage involvement as well as by multiple relapses despite griseofulvin therapy. Dermatophytic disease is a serious life-threatening disease due to its inexorable evolution toward visceral involvement. The improvement of patient's immune system associated with antifungal therapy may be the best treatment.

En bloc excision of proximal nail fold for treatment of chronic paronychia.

BACKGROUND: Chronic paronychia is a very recalcitrant dermatosis, which is particularly prevalent in housewives. Medical treatment for this condition is unsatisfactory in a significant number of cases. Surgical approach forms an important part of management, however, this area has received little attention. Various surgical approaches have been tried in the past but a comparative analysis has not been attempted. OBJECTIVES: The present study aims at assessing the efficacy of en bloc excision of proximal nail fold (PNF). Moreover, a comparative analysis has been undertaken to assess whether or not simultaneous nail plate avulsion improves the treatment outcome. METHODS: Thirty patients of chronic paronychia with nail plate irregularities were randomly divided into two treatment groups (15 patients each). After a detailed evaluation, en bloc excision of PNF with or without nail plate removal was performed. Postoperative measures were advised and the patients were kept under regular follow-up thereafter. Assessment of postoperative complications was also performed. RESULTS: Twelve patients in group I and 13 patients in group II completed the treatment protocol. Of these, 70% of patients were cured in group II (en bloc excision with nail avulsion) whereas only 41% were cured in group I (en bloc excision without nail avulsion). CONCLUSION: En bloc excision of the PNF is a useful method in recalcitrant chronic paronychia. Simultaneous avulsion of the nail plate improves the surgical outcome. Strict avoidance of irritant exposure is necessary to ensure complete treatment and prevent recurrence.

[Fungal and bacterial nail infections]. / Infections mycosiques et bactériennes de l'appareil unguéal.

Fungal and bacterial infections are very common causes of nail deformity. The majority of fungal nail infections are caused by dermatophytes. Dermatophytosis result from a human contamination. A dermatophyte is always a pathogenic agent. Very effective drugs are available to treat dermatophyte nail infections. Yeasts of the genus Candida, notably C. albicans are the second most common cause of nail infection. The infections of nails due to Candida and bacteria are related with Candida sp and bacteria which are common commensals of the gastrointestinal tract, vagina or skin. Except C. albicans which is always a pathogen of skin, the other species of Candida and the bacteria could be a commensal of the skin, a colonizer of a dermatological disease or a true pathogen of nail. It is important to consider these different situations. More rarely, environmental moulds, most often known as saprophytic agents, can affect nails. They do not respond to conventional antifungal drugs. So, their diagnosis do not suffer any error. In order to evaluate properly the patient with possible fungal or bacterial infection of nails and also to choice an accurate therapy, the laboratory confirmation is essential. Clinical diagnosis is not sufficient to distinguish an infection of nails from a dermatological disease (psoriasis, traumatism) and to identify the responsible agent.