Recalcitrant dermatophytosis treatment

Skin barrier function defect - A marker of recalcitrant tinea infections

Puneet Bhargava, Shivi Nijhawan, Heena Singdia, Taniya Mehta
Department of Dermatology, Sawai Mansingh Medical College, Jaipur, Rajasthan, India

Correspondence Address:
Puneet Bhargava
D-60, Nahesh Marg, Bapunagar, Jaipur - 302 015, Rajasthan
India

Source of Support: None, Conflict of Interest: None

DOI:10.4103/idoj.IDOJ_434_19

Context: Recently, there has been an increase in the number of chronic, recurrent, and recalcitrant dermatophytosis. Many factors implicated are barrier defects, aberrant host immune response, application of steroids or other irrational combination creams, transmission within family, occlusive clothing, poor hygienic conditions, poor compliance, drug resistance and virulence of the infecting strain. Transepidermal water loss [TEWL] is an important index in accessing the barrier function of skin. Aim: To ascertain the role of TEWL from the lesional skin and its effect on the cure rate and relapse in patients of tinea cruris. Materials and Method: A hospital based prospective comparative study was conducted for 1 year. A total of 200 patients of tinea cruris diagnosed clinically and by KOH examination, were included in the study. TEWL was calculated using Tewameter TM300 open chamber probe of Courage and Khazaka, Cologne, Germany. Patients were classified according to the TEWL values into Group A [patients with abnormal TEWL] and Group B [normal TEWL]. Both groups were given oral itraconazole and antihistamines for 4 weeks. The cure rates and recurrence rates of both the groups were analyzed and compared. Results: In the Group A, i.e., patients of tinea cruris with abnormal TEWL, only 28% of the patients showed clinical improvement at the end of 1 month. Out of those cured, 78.57% of the cases showed recurrence after 2 months of completion of therapy. In Group B, i.e., patients of tinea cruris with normal TEWL, 69% [n = 69] of the patients showed clinical improvement at the end of 1 month. Out of those cured, only 21.74% of the cases [n = 15] showed recurrence. Conclusion: The cases of tinea cruris with abnormal TEWL show significant decrease in cure rates and significant relapse rates among those initially cured.

Keywords:Recalcitrant tinea infections, skin barrier defect, transepidermal water loss

Dermatophytosis is a common infection of the skin, hair or nails, i.e., colonization of keratinized tissue caused by dermatophytes, a group of related filamentous fungi. These infections are caused by species of three generaTrichophyton, Epidermophyton, and Microsporum. Among all fungal infections, infections caused by the dermatophytes are the most frequent forms of human infections, affecting more than 20%25% of the world's population.[1]

Based on their natural habitat, dermatophytes are classified into three groupsGeophilic, Zoophilic, and Anthrophilic species.

Anthropophilic species include Trichophyton rubrum, Trichophyton schoenleinii, Trichophyton concentricum, Trichophyton tonsurans, Trichophyton mentagrophytes var. interdigitale, Microsporum gypseum, Microsporum audouinii, Microsporum ferrugineum, and Epidermophyton floccosum. These anthropophilic species are responsible for the majority of human infections.

Superficial fungal infections had always been simple to treat with the basket of antifungal agents available; however, recently, an alarming trend of these dermatosis is being observed, with substantial change in the clinical profile of patients associated with an increase in the number of chronic, recurrent, and recalcitrant dermatophytosis.[2],[3],[4]

Recalcitrant dermatophytosis refers to relapse, recurrences, reinfection, persistence, or chronic infections, and possibly microbiological resistance.[5]

Dermatophytosis is considered to be recurrent when there is recurrence of the disease [lesions] after 4 weeks of completion of approved systemic therapy.[6]

Relapse denotes the occurrence of dermatophytosis [lesions], after a longer period of infection-free interval [68 weeks] in a patient who has been cured clinically.[7]

Dermatophytosis is considered to be chronic when the patients who have suffered from the disease for more than 6 months to 1 year, with or without recurrence, in spite of being adequately treated.[7]

Now-a-days, antifungal resistance is also thought to be an important cause for treatment failure in case of dermatophytosis. Other factors such as barrier defects, remains neglected.

Transepidermal water loss [TEWL] measurement is the most widely used objective measurement for assessing the barrier function of the skin.[8]

TEWL represents the diffusion of condensed water through a fixed area of stratum corneum to the skin surface per unit time [9],[10] and is measured in grams/m2/hour.

Our study highlights the role of transepidermal water loss from the lesional skin and its effect on the cure rate and relapse in patients of Tinea cruris.

This was a hospital based prospective comparative study. A total of 200 patients of tinea cruris, attending the dermatology outpatient department of Sawai Mansingh Hospital, Jaipur, not on any topical or systemic treatment previously were included in the study. A written and informed consent was obtained from each patient. The study was conducted over a period of 1 year.

The cases were diagnosed clinically and by KOH examination. Ethical clearance was taken up for the study.

TEWL was calculated in these patients from the lesional skin over the right inguinal region, according to guidelines developed by 5th International Conference on Occupational and Environmental exposure of skin to chemicals [OEESC] using Tewameter TM300 open chamber probe of Courage and Khazaka, Cologne, Germany.

Transepidermal water loss is calculated by measuring the water vapor pressure [VP] gradient at the skin surface, which is considered constant in the absence of external convection currents. In the open-chamber method, the VP gradient is calculated by measuring the difference in VP between two distinct points aligned perpendicularly to the skin surface. VP is calculated as the product of RH [Relative humidity] and saturated VP, which is dependent on temperature.

Prior to measurement of TEWL and/or skin hydration, the study participant were acclimatized to the measurement environment to avoid errors caused by environmental temperature or sweating.

In accordance to OEESC guidelines, the affected area was left open for 20 minutes prior to the test at relative humidity of 50% and ambient temperature of 22°C.

TEWL was measured in grams/m2/hour. A value of >25 grams/m2/hour was considered as abnormal or critical. These patients were divided into 2 groups on the basis of TEWL values.

Group A included patients of tinea cruris with abnormal TEWL, whereas Group B included age and sex matched patients of Tinea cruris with a normal TEWL. Both the groups were given 200 mg Itraconazole OD + oral antihistamines. Although Itraconazole 200 mg single dose is unapproved formulation by USFDA, but the skin department in our institution follows both the regimens, i.e., Itraconazole 200 mg OD as well as 100 mg BD. Little differences are observed in cure rates after both regimens. Cure was defined on the basis of clinicalobservation, and KOH examination. Culture studies could not be performed.

Cure rate of the two groups was compared 1 month later, whereas, recurrence of the two groups was compared 3 months later.

ŸMedcalc 16.4 version software was used to analyze data presented as proportion.

Chi square test was used for analysis and P value