Tinea imbricata in the Americas

Annular skin lesions in infancy

Annular skin lesions have a unique morphology, and the dramatic appearance of these skin eruptions in infants can cause concern for parents and clinicians. Annular lesions appearing during infancy (defined here as birth to 1 year of age) lend to a broad differential, ranging from benign cutaneous disorders to severe systemic diseases. This review summarizes the pathogenesis, clinical and histopathologic findings, and management options of possible etiologies for annular skin lesions in infants, including annular erythema of infancy, neonatal lupus erythematosus, dermatophyte infections, hemorrhagic edema of infancy, and urticaria multiforme.

Review on host-pathogen interaction in dermatophyte infections

Dermatophytosis is a common superficial fungal infection of the skin and its appendages caused by dermatophytes. Recent times have witnessed a dynamic evolution of dermatophytes driven by their ecology, reproduction, pathogenicity and host immune response, influenced by population migration and socioeconomic status. Dermatophytes establish infection following successful adherence of arthroconidia to the surface of keratinized tissues. The proteolytic enzymes released during adherence and invasion not only ascertain their survival but also allow the persistence of infection in the host. While the cutaneous immune surveillance mechanism, after antigen exposure and presentation, leads to activation of T lymphocytes and subsequent clonal expansion generating effector T cells that differentially polarize to a predominant Th17 response, the response fails to eliminate the pathogen despite the presence of high levels of IFN-γ. In chronic dermatophytosis, antigens are a constant source of stimulus promoting a dysregulated Th17 response causing inflammation. The host-derived iTreg response fails to counterbalance the inflammation and instead polarizes to Th17 lineage, aggravating the chronicity of the infection. Increasing antifungal resistance and recalcitrant dermatophytosis has impeded the overall clinical remission. Human genetic research has the potential to generate knowledge to explore new therapeutic targets. The review focuses on understanding specific virulence factors involved in pathogenesis and defining the role of dysregulated host immune response against chronic dermatophytic infections for future management strategies.

Annular skin lesions in infancy

Annular skin lesions have a unique morphology, and the dramatic appearance of these skin eruptions in infants can cause concern for parents and clinicians. Annular lesions appearing during infancy (defined here as birth to 1 year of age) lend to a broad differential, ranging from benign cutaneous disorders to severe systemic diseases. This review summarizes the pathogenesis, clinical and histopathologic findings, and management options of possible etiologies for annular skin lesions in infants, including annular erythema of infancy, neonatal lupus erythematosus, dermatophyte infections, hemorrhagic edema of infancy, and urticaria multiforme.

A Case of Tinea Pseudoimbricata Due to Trichophyton tonsurans Induced by Topical Steroid Application

Tinea imbricata and tinea pseudoimbricata are variant types of tinea corporis characterized by annual-ring-shaped erythema. Although the skin lesions manifest similar symptoms, these two diseases are classified based on causative fungi. The former is caused by Trichophyton concentricum, an anthropophilic dermatophyte, and the latter is caused by dermatophytes other than T. concentricum, commonly zoophilic fungi such as Trichophyton mentagrophytes complex. Here, we report a 27-year-old Japanese male diagnosed with tinea pseudoimbricata attributed to Trichophyton tonsurans, an anthropophilic dermatophyte. We suspected that application of steroid ointment caused the annular pattern of his skin lesions. After three months use of topical luliconazole cream, treatment was finished. We also summarize the knowledge about tinea pseudoimbricata through previous reports with bibliographical consideration.

Tinea Pseudoimbricata as a Unique Manifestation of Steroid Abuse: A Clinico-Mycological and Dermoscopic Study from a Tertiary Care Hospital

Background:

Tinea pseudoimbricata, characterized by concentric scaly rings simulating Tinea imbricata is caused by dermatophytes other than Trichophyton concentricum. It is reported to occur in patients with steroid abuse and in immunocompromised individuals.

Aim:

To study the clinico-mycological profile and dermoscopic features of T. pseudoimbricata in immunocompetent patients.

Methods:

We have evaluated 14 consecutive, clinically diagnosed patients of T. pseudoimbricata with positive 10% potassium hydroxide (KOH) examination and culture, seen over a period of 6 months. Dermoscopy was performed in all patients. The demographic, clinical, and mycological features of each patient were recorded on a predesigned proforma.

Results:

There were seven male and seven female patients with a mean age of 27.6 years and a mean disease duration of 3.8 months. All patients gave a history of application of potent or super-potent topical steroid with or without oral/injectable steroid for varying duration. Culture isolates were Trichophyton mentagrophytes complex and Trichophyton rubrum in 11 and 3 patients, respectively. Dermoscopic analysis showed features of steroid abuse in majority of the patients.

Limitation:

A small sample size was the limitation of our study.

Conclusion:

T. pseudoimbricata is a special subset of Tinea incognito caused by injudicious and inappropriate use of topical steroid. The typical appearance should alert the dermatologists regarding the possible abuse of steroids. Most common species isolated on culture was T. mentagrophytes complex.

Tinea Imbricata: An Overview

BACKGROUND

Tinea imbricata is a chronic superficial mycosis caused mainly by Trichophyton concentricum. The condition mainly affects individuals living in primitive and isolated environment in developing countries and is rarely seen in developed countries. Physicians in nonendemic areas might not be aware of this fungal infection.

OBJECTIVE

To familiarize physicians with the clinical manifestations, diagnosis, and treatment of tinea imbricata.

METHODS

A PubMed search was completed in Clinical Queries using the key terms "Tinea imbricata" and "Trichophyton concentricum". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, reviews, and case reports. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

The typical initial lesions of tinea imbricata consist of multiple, brownish red, scaly, pruritic papules. The papules then spread centrifugally to form annular and/or concentric rings that can extend to form serpinginous or polycyclic plaques with or without erythema. With time, multiple overlapping lesions develop, and the plaques become lamellar with abundant thick scales adhering to the interior of the lesion, giving rise to the appearance of overlapping roof tiles, lace, or fish scales. Lamellar detachment of the scales is common. The diagnosis is mainly clinical, based on the characteristic skin lesions. If necessary, the diagnosis can be confirmed by potassium hydroxide wet-mount examination of skin scrapings of the active border of the lesion which typically shows short septate hyphae, numerous chlamydoconidia, and no arthroconidia. Currently, oral terbinafine is the drug of choice for the treatment of tinea imbricata. Combined therapy of an oral antifungal agent with a topical antifungal and keratolytic agent may increase the cure rate.

CONCLUSION

In most cases, a spot diagnosis of tinea imbricata can be made based on the characteristic skin lesions consisting of scaly, concentric annular rings and overlapping plaques that are pruritic. Due to popularity of international travel, physicians involved in patient care should be aware of this fungal infection previously restricted to limited geographical areas.

Tropical Skin Diseases in Children: A Review- Part I

Because of travel and migration patterns, tropical skin diseases are now seen all around the world, not just in tropical or developing countries. Nutrition, housing, and environmental factors play an important role in these infectious diseases, so when they appear out of their normal environments, their classic presentation may vary. Tropical diseases can also present differently in childhood, making their recognition, diagnosis, and management a clinical challenge. Health care providers in developed countries need to be familiar with tropical skin diseases and be able to diagnose them in returning travelers or immigrants in order to optimize care. This article aims to review the epidemiologic, clinical, diagnostic, and therapeutic aspects of some of the most common tropical dermatologic conditions in children.

Tinea Imbricata in an Italian Child and Review of the Literature

Tinea imbricata is a chronic superficial mycosis caused by Trichophyton concentricum. It is characterized by widespread, annular, concentric, squamous lesions. Tinea imbricata is endemic in three geographical areas: Southwest Pacific, Southeast Asia, and Central and South America. Tinea imbricata in travelers returning from endemic areas is exceptionally rare. We report a case of tinea imbricata in an Italian child who acquired the infection during a trip to Solomon Islands. Three cultures were positive for T. concentricum. The patient was successfully treated with griseofulvin and terbinafine cream.

Mycology - an update part 2: dermatomycoses: clinical picture and diagnostics

Most fungal infections of the skin are caused by dermatophytes, both in Germany and globally. Tinea pedis is the most frequent fungal infection in Western industrial countries. Tinea pedis frequently leads to tinea unguium, while in the elderly, both may then spread causing tinea corporis. A variety of body sites may be affected, including tinea glutealis, tinea faciei and tinea capitis. The latter rarely occurs in adults, but is the most frequent fungal infection in childhood. Following antifungal treatment of tinea unguium and also tinea capitis a dermatophytid or hyperergic reaction to dermatophyte antigens may occur. Yeast infections affect the mucous membranes both of the gastro-intestinal system and the genital tract as candidiasis mostly due to Candida albicans. Cutaneous candidiasis affects predominantely the intertriginous regions such as groins and the inframammary area, but also the intertriginous space of fingers and toes. In contrast, pityriasis versicolor is a superficial epidermal fungal infection primarily on the the trunk. Mold infections are rare in dermatology; they play a role nearly exclusively in nondermatophyte-mold (NDM) onychomycosis. The diagnosis of dermatomycoses comprises the microscopic detection of fungi using the potassium hydroxide preparation or alternatively the fluorescence optical Blankophor preparation together with culture. The histological fungal detection with PAS staining possesses a high sensitivity, and it should play a more important role in particular for diagnosis of onychomycosis. Molecular biological methods, based on the amplification of fungal DNA with use of specific primers for the distinct causative agents are on the rise. With PCR, such as dermatophyte-PCR-ELISA, fungi can be detected directly in clinical material in a highly specific and sensitive manner without prior culture. Today, molecular methods, such as Matrix Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry (MALDI TOF MS) as culture confirmation assay, complete the conventional mycological diagnostics.

Tinea imbricata as a clue to occult immunodeficiency

Tinea imbricata (TI) is a geographically restricted dermatophytosis with distinctive clinical and immunologic features. We present a case of TI occurring in a native Brazilian child with previously undiagnosed human immunodeficiency virus infection. Physicians should bear in mind that diagnosis of TI may be a clinical clue to potentially serious underlying immunodeficiency.

The role of dendritic cells in the innate recognition of pathogenic fungi (A. fumigatus, C. neoformans and C. albicans)

Dendritic cells (DCs) are the bridge between the innate and adaptive immune system. DCs are responsible for sensing and patrolling the environment, initiating a host response and instructing the proper adaptive immune response against pathogens. Recent advances in medical treatments have led to increased use of immunosuppressive drugs, leading to the emergence of fungal species that cause life-threatening infections in humans. Three of these opportunistic fungal pathogens: Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans pose the biggest concern for the immune-compromised host. Here we will review the interactions between DCs and these fungal pathogens, the receptors expressed on DCs that mediate these responses and the signaling mechanisms that shape the adaptive host response.