Longitudinal melanonychia caused by trichophyton rubrum. Histochemical and ultrastructural study of two cases

Current therapeutic insights regarding problematic fingernails and toenails in the Republic of Korea

BACKGROUND

Problematic nails and toenails are infected by germs and increasingly have many causes.

AIMS

To investigate the types and treatment of problematic nails and toenails, we focused on bacteria that may appear in problematic nail toenail symptoms.

METHODS

We have searched for PubMed and Google Scholar and correlated the words Onychomycosis, Tinea ungium, Melanonychia, and ingrown toenail related to symptoms.

RESULTS

To measure onychomycosis, KOH tests and fungal culture tests will be used. Treatment can be treated with full-body treatment using anti-fungal agents and local treatment (laser therapy) that can minimize the side effects. A biopsy should be performed when Melanonychia is diagnosed with brown or black pigments on the patient's fingernail plate. Moreover, ingrown toenail surgical treatment can be improved by acquired lifestyle.

CONCLUSIONS

There are many different types of treatments, but many studies show that problematic nail and toenail improvement periods are long and treatment success rates are low.

Onychotillomania: Diagnosis and Management

Onychotillomania, defined as self-induced trauma to the nail unit, either by picking or pulling at the nails, affects 0.9% of the population. It may lead to severe irreversible nail dystrophy, melanonychia, or infections. Although no large clinical trials have assessed the efficacy of treatments, cognitive-behavioral therapy, physical barrier methods, and pharmacological treatments have shown some benefits in case reports. The objective of this article is to review the prevalence, diagnostic criteria, etiology, historical and physical examination findings, pathological features, and current treatment methods. Onychotillomania remains a clinical challenge to dermatologists, pediatricians, internists, and psychiatrists in practice, as there are no evidence-based treatment methods.

Fontana-Masson stain in fungal infections

BACKGROUND

Fontana-Masson (FM) staining is a histopathology technique used to identify dematiaceous fungi. The result often guides initial species identification and antifungal treatment; however, there is evidence that nondematiaceous fungi might react with this stain. Few studies in the current literature address this issue.

OBJECTIVE

Our aim was to classify the FM staining patterns of common fungal pathogens for use by pathologists attempting to accurately identify fungi on histopathologic examination.

METHODS

In total, 132 cases of culture proven mycoses were identified. We stained tissue with 2 different FM protocols and recorded the intensity and distribution of results.

RESULTS

There was variability in staining, and many nondematiaceous fungi showed positivity, including Zygomycetes, Aspergillus, and Fusarium spp.

LIMITATIONS

The study was limited by the number of cases. Of 132 cases identified, 112 cases had adequate tissue left after sectioning deeper into the block.

CONCLUSION

Nondematiaceous fungi frequently stained positive with FM. The course of treatment should not be based on the result of this stain alone. Histopathology should be examined in multiple tissue sections, and therapy should be determined on the basis of clinical context and culture results.

Fungal Melanonychia

Melanonychia is characterized by tan, brown, or black pigmentation within the nail plate. Fungal melanonychia is rare and may simulate longitudinal melanonychia caused by melanocytic lesions. We report six cases of fungal melanonychia which were confirmed histopathologically or mycologically. On culture, Candida and/or Aspergillus species were isolated in four patients. The nail pigmentation improved after treatment with antifungal agents in all cases, but one patient experienced a new lesion on another nail after cessation of treatment. Fungal infection should be considered as a cause of melanonychia, and fungal melanonychia should be differentiated from the melanonychia caused by melanocytic lesions, particularly by subungual melanoma.

Longitudinal melanonychia: when to biopsy and is dermoscopy helpful?

Longitudinal melanonychia (LM) is a common presenting problem in general dermatology, and represents a diagnostic challenge to clinicians given its broad differential diagnosis that includes both benign and malignant entities. The decision of when a biopsy is required is incredibly challenging for dermatologists. Dermoscopy is a noninvasive technique that enhances the clinical evaluation of LM, and has demonstrated potential in improving the clinical decision making as to whether or not to biopsy LM. However, it is critical for clinicians to understand the limitations of dermoscopy, and that although it is able to add new criteria for the diagnosis of ungual pigmentation, it does not replace histopathologic diagnosis. Biopsy of the nail unit should be performed in any case where doubt based on the clinical evaluation exists.

Melanogenesis in dermatophyte species in vitro and during infection

Dermatophytes are keratinophilic fungi that are the most common cause of fungal skin infections worldwide. Melanin has been isolated from several important human fungal pathogens, and the polymeric pigment is now recognized as an important virulence determinant. This study investigated whether dermatophytes, including Trichophyton rubrum, Trichophyton mentagrophytes, Epidermophyton floccosum and Microsporum gypseum, produce melanin or melanin-like compounds in vitro and during infection. Digestion of the pigmented microconidia and macroconidia of dermatophytes with proteolytic enzymes, denaturant and hot concentrated acid yielded dark particles that retained the size and shape of the original fungal cells. Electron spin resonance spectroscopy revealed that particles derived from pigmented conidia contained a stable free radical signal, consistent with the pigments being a melanin. Immunofluorescence analysis demonstrated reactivity of a melanin-binding mAb with the pigmented conidia and hyphae, as well as the isolate particles. Laccase, an enzyme involved in melanization, was detected in the dermatophytes by an agar plate assay using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as the substrate. Skin scrapings from patients with dermatophytoses contained septate hyphae and arthrospores that were reactive with the melanin-binding mAb. These findings indicate that dermatophytes can produce melanin or melanin-like compounds in vitro and during infection. Based on what is known about the function of melanin as a virulence factor of other pathogenic fungi, this pigment may have a similar role in the pathogenesis of dermatophytic diseases.

Clinical guidelines for the recognition of melanoma of the foot and nail unit

Malignant melanoma is a life threatening skin tumour which may arise on the foot. The prognosis for the condition is good when lesions are diagnosed and treated early. However, lesions arising on the soles and within the nail unit can be difficult to recognise leading to delays in diagnosis. These guidelines have been drafted to alert health care practitioners to the early signs of the disease so an early diagnosis can be sought.

A case of melanonychia due to Candida albicans

Candida species rarely cause black pigmentation of infected nails and only a few cases have been reported in the literature. We describe a 53-year-old white man who had diffuse melanonychia of the fourth right fingernail due to C. albicans. A progressive dark pigmentation of his nail appeared over 6 months, following paronychial inflammation. The melanonychia was associated with brittleness. There was no onycholysis or hyperkeratosis. Direct examination with potassium hydroxide demonstrated round yeast cells in the specimen. The samples were cultured on Sabouraud glucose agar containing chloramphenicol at 27 degrees C and showed white growth after a few days. The patient was successfully treated with systemic itraconazole.

Longitudinal melanonychia of the toenails with presence of Medlar bodies on biopsy

A 9-year-old girl presented with a 2-year history of pigmented streaks on her second right toenail as well as on her fourth and fifth left toenails. The patient was otherwise asymptomatic with no other physical findings. Owing to parental concern, a biopsy was performed, which revealed numerous bacteria as well as Medlar bodies overlying the nail bed with no evidence of a nevomelanocytic lesion. To our knowledge, this is the first report of Medlar bodies causing pigmented streaks in the toenails.

Onychomycosis: strategies to improve efficacy and reduce recurrence

Fungal infections may be difficult to treat for several reasons. It is important to obtain the correct diagnosis, and select the appropriate antifungal agent and route. General considerations that may be associated with recurrent infections are, a genetic predisposition and suboptimal bioavailability of drug, resulting in insufficient concentration at the target site. The aetiologic organism, the severity of disease, other coexisting diseases, concomitant drug intake, and the presence of fungal infection at other sites are some factors that determine the choice of antifungal therapy and its route of administration, oral vs. topical lacquer. Local factors such as the thickness of the nail, presence of lateral onychomycosis, longitudinal spike, dermatophytoma and severe onycholysis are some factors that may determine the choice of secondary measures such as mechanical or topical treatment. Booster or supplemental therapy may be of benefit when the response to initial treatment is poorer than expected and unlikely to result in complete response. Steps should be taken to reduce the possibility of recurrence once cure has been achieved.

The physical basis of cosmetic defects of the nail plate

Cosmetic defects of the nail cover a range of changes. Some are variants of normal which are considered unattractive, others are part of the normal ageing process and some changes are manifestations of local or systemic disease. Interpretation of these changes relies on recognition of the specific characteristics in question and an understanding of the anatomy and biology of nails. In many instances, therapies are limited and explanation of the changes represents one of the most useful contributions the professional can make to the affected individual. This article covers some of the most common cosmetic defects of nail involving colour, surface, brittleness and behaviour of surrounding tissues. Understanding of the physical basis of these defects is limited in many cases, but current thinking is recorded.

Longitudinal melanonychia

BACKGROUND

Ungual melanoma is the most serious disease affecting the nail. The majority start with a longitudinal brown streak in the nail.

OBJECTIVE

To outline the different nail pigmentations, their differential diagnoses, treatment, and prognosis.

METHOD

Clinical and histologic evaluation of dark nail pigmentations.

CONCLUSION

Brown to black nail pigmentation may be due to different coloring substances of exogenous and endogenous origin. Exogenous pigmentations usually are not streaky or do not present as a stripe of even width with regular borders. Bacterial pigmentation, most commonly due to Pseudomonas aeruginosa or Proteus spp., have a greenish or grayish hue and the discoloration is often confined to the lateral edge of the nail. Subungual hematoma may result from a single heavy trauma or repeated microtrauma which often escapes notice. The latter is usually found on the medial aspect of the great toe. Although oval in shape, it commonly does not form a neat streak. Melanin pigmentation in the form of a longitudinal streak in the nail is due to a pigment-producing focus of melanocytes in the matrix. Neither the color intensity nor the age of the patient are proof of benignity or malignancy although subungual melanomas are very rare in children and malignant longitudinal melanonychia is usually wider than 5 mm. Hutchinson's melanotic whitlow, nail dystrophy, and a bleeding mass strongly suggest malignancy. Treatment is as conservative as possible in order to keep the tip of the digit; once the melanoma is completely removed, amputations have not been shown to prolong the disease-free survival time.

Tinea unguium in Lahore, Pakistan

During a period of 1 year, out of 202 clinically suspected cases of tinea unguium, 53 (26%) were confirmed by mycological cultures for dermatophytes. Trichophyton rubrum was the most common fungus isolated in 46 (87%) patients, followed by T. violaceum in four (7%), T. interdigitale in two (4%) and Epidermophyton floccosum in one (2%). The disease was more common in adult males and fingernails were found to be affected more often than toenails. The distal and lateral variety was seen in 41 (77%) patients, total secondary dystrophic type in 11 (21%) and proximal subungual type in one (2%). Clinical diagnosis alone is not reliable and mycological confirmation is mandatory for this potentially curable disease.

Onychomycosis in the elderly

Onychomycosis is found more frequently in the elderly, and in more males than females. Onychomycosis of the toes is usually caused by dermatophytes, most commonly Trichophyton rubrum and T. mentagrophytes. The most common clinical presentations are distal and lateral subungual onychomycosis (which usually affects the great/first toe) and white superficial onychomycosis (which generally involves the third/fourth toes). Only about 50% of all abnormal-appearing nails are due to onychomycosis. In the remainder, trauma to the nail, psoriasis and conditions such as lichen planus should be considered in the differential diagnosis. Therefore, the clinical impression of onychomycosis should be confirmed by mycological examination, whenever possible. The management of onychomycosis may include no therapy, palliative treatment with mechanical or chemical debridement, topical antifungal therapy, oral antifungal agents or a combination of treatment modalities. In the US, the only new oral agents approved for treatment of onychomycosis are terbinafine and itraconazole. Fluconazole is approved for onychomycosis in some other countries. Ciclopirox nail lacquer has recently been approved in the US for the treatment of onychomycosis. In some other countries topical agents such as amorolfine are also used. Griseofulvin and ketoconazole are no longer preferred for the treatment of onychomycosis. The new oral antifungal agents are effective and well tolerated in the elderly. Patient selection should be based on the history (including systems review and medication record), examination and baseline monitoring, if indicated. Laboratory monitoring during therapy for onychomycosis varies among physicians. A combination of removal of the diseased nail plate or local measures and oral antifungal therapy may be optimal in certain instances, e.g. when lateral onychomycosis or dermatophytoma are present. For dermatophyte toe onychomycosis the recommended duration of therapy with terbinafine is 250 mg/day for 12 weeks. For itraconazole (pulse) the regimen is 200 mg twice daily for 1 week on, 3 weeks off, repeated for 3 consecutive pulses and with fluconazole the regimen is 150 to 300 mg once weekly given for a usual range of 6 to 12 months or until the nail plate has grown out. In some instances, if extra therapy is required, one suggestion is that 4 weeks of terbinafine or an extra pulse of itraconazole are given between months 6 and 9 from the start of therapy. Once cure has been achieved, it is important to counsel patients on the strategies of reducing recurrence of disease.

Onychomycosis caused by Scytalidium dimidiatum. Report of two cases. Review of the taxonomy of the synanamorph and anamorph forms of this coelomycete

The authors report two cases of onychomycosis in the dystrophic form, one of them involving an HIV-positive patient, provoked by Scytalidium dimidiatum, previously called Scytalidium lignicola. The subject is reviewed from the taxonomic viewpoint, considering the anamorph Hendersonula toruloidea as a synonym of Nattrassia mangiferae, and having Scytalidium dimidiatum as the major synanamorph. According to many mycologists, Scytalidium hyalinum may be a separate species or a hyaline mutant of Scytalidium dimidiatum. Scytalidium lignicola Pesante 1957 was considered to be the type-species of the genus by ELLIS (1971)13 and later to be a "conidial state" of Hendersonula toruloidea by the same author, today known as Nattrassia mangiferae. The microorganism lives only on the roots of certain plants (mainly Platanus and Pinus). It produces pycnidia and is not considered to be a pathogen, although it is considered as a possible emerging agent capable of provoking opportunistic fungal lesions. The importance of this topic as one of the most outstanding in fungal taxonomy, so likely to be modified over time, as well as its interest in the field of dermatologic mycology, are emphasized.