Dermatophytosis
Mahmoud A. Ghannoum, John R. Perfect in Antifungal Therapy, 2019
Tinea corporis, or “ringworm,” is an infection of the glabrous skin, usually on the trunk and extremities. The predominant pathogens are T. rubrum and to a lesser extent T. tonsurans. Infection in wrestlers is referred to as tinea corporis gladiatorum and is most often caused by T. tonsurans. In teams without known epidemics, prevalence rates ranged from 20% to 44% [11]. Majocchi’s granuloma, tinea imbricata, and tinea incognito are three variants of tinea corporis. Deep-seated tinea corporis, referred to as Majocchi’s granuloma, is most often due to T. rubrum or T. mentagrophytes. It occurs most frequently in women and is typically located on the lower extremities [4] (Figure 15.4). Tinea imbricata is caused by T. concentricum and is limited geographically to southwest Polynesia, Melanesia, Southeast Asia, India, and Central America. Lastly, tinea incognito is a term applied to atypical clinical lesions of tinea that have been treated with topical corticosteroids (Figure 15.5).
Chronic erythematous rash and lesions on trunk and limbs
Richard Ashton, Barbara Leppard in Differential Diagnosis in Dermatology, 2021
Tinea incognito develops when tinea corporis (ringworm) is inadvertently treated with topical steroids. This alters the clinical appearance so that the lesions have no appreciable scale, and the distribution may be more extensive than usual (Fig. 8.56). The distribution may even be symmetrical (Fig. 8.55). Scraping the edge will reveal fungus. Treat by stopping the application of the topical steroid and apply an anti-fungal cream (see p. 150).
Hair and groin problems
Manu Shah, Ariyaratne de Silva in The Male Genitalia, 2018
Tinea may be found in other sites such as the nails, the feet, the peri-anal area and on the body. It may be extremely difficult to diagnose if it has been modified by the use of topical corticosteroids (then called ‘tinea incognito’). The rash then looks non-specific, often eczematous but without the scaly edge.
Strategies to improve the diagnosis and clinical treatment of dermatophyte infections
Published in Expert Review of Anti-infective Therapy, 2023
In recent years, noninvasive and painless microscopes, which are referred to as reflectance confocal microscopes, have directly enabled the detection of fungal elements in patients, wherein a 10% KOH solution is first dripped onto the specimen to ensure that the fungal structures can be easily observed. The use of these microscopes, as well as the potential use of cheaper and handheld microscopes in the future, will facilitate these examinations [11]. This is especially true in cases of Majocchi’s granuloma and tinea incognito, wherein KOH examination can yield a negative result, and fungal elements can be detected without biopsy (Figures 5A and 5B) [12].
The association of isoconazole–diflucortolone in the treatment of pediatric tinea corporis
Published in Journal of Dermatological Treatment, 2018
Stefano Veraldi, Rossana Schianchi, Paolo Pontini, Alberto Gorani
As previously mentioned, we believe that staphylococcal superinfections of tinea corporis in atopic children are due to scratching. A once daily application of isoconazole and diflucortolone cream for 5–7 days, followed by the application of a specific antimycotic, reduces the itching, the scratching, and bacterial superinfections. Furthermore, it was demonstrated that isoconazole is effective in vitro on S. aureus: the minimal inhibitory concentration was 6.3 μg ml−1 (2–6). However, isoconazole has no activity on Gram-negative bacteria (4,5). The antibacterial action of isoconazole involves an increase in reactive oxygen substances (ROS). The increased ROS levels within bacteria results in oxidative stress that causes apoptosis and cell death (5). In 2012, two of us (SV and RS) published the results of a multicenter, sponsor-free study that evaluated the clinical and mycological efficacy and tolerability of the combination isoconazole–diflucortolone cream (twice daily for one week, followed by isoconazole cream alone, twice daily for two weeks) compared with a monotherapy with isoconazole cream (twice daily for three weeks) in adult patients with tinea inguinalis. The combination isoconazole–diflucortolone was superior to isoconazole alone regarding erythema and pruritus: both of them resolved in a larger percentage of patients and more quickly. No side effects were reported or observed in both groups. Mycological cure rates were similar in both groups: 83.9% in the monotherapy group and 85.2% in the combination group (7). The combination isoconazole–diflucortolone showed to be effective in some anedoctical cases of tinea corporis (8), tinea cruris (9–11), tinea pedis (12–14), tinea incognito (15), and intertrigo (16–19) and balanitis (18) by Candida albicans. Our study in atopic children with tinea corporis superinfected by S. aureus confirms that a topical therapy with the association isoconazole–diflucortolone can be useful for several reasons: (a) isoconazole eradicates causative microorganisms, (b) diflucortolone induces a rapid improvement of pruritus, (c) another benefit is the increased bioavailability of isoconazole in the skin, when it is applied together with diflucortolone: due to the local vasoconstrictive action of diflucortolone, the dispersal of isoconazole via the circulation is delayed (20,21). After 24 h of exposure to the combination isoconazole–diflucortolone, epidermal, and dermal isoconazole concentrations reach 120 and 13 μg ml−1, respectively, compared to 40 and 4 μg ml−1, respectively, for isoconazole alone (21): the duration of antimycotic activity is therefore prolonged, (d) the incorporation of a corticosteroid reduces the risks of irritant and allergic contact dermatitis that can be caused by topical antimycotics, (e) finally, the incorporation of a topical corticosteroid reduces scratching and the incidence of bacterial superinfections. Similar clinical results were observed in single pediatric cases of tinea corporis (22–25). The possibility that topical corticosteroids induce skin atrophy is purely theoretical, if we consider the single daily application and the duration (5–7 days).
Related Knowledge Centers
- Bacteria
- Betamethasone
- Dermatitis
- Fungal Infection
- Corticosteroid
- Dermatophytosis
- Infection
- Skin
- Skin Condition
- Impetigo