|Year : 2021 | Volume
| Issue : 1 | Page : 49-53
Efficacy and safety of 88% phenol application versus cryotherapy in repigmentation of idiopathic guttate hypomelanosis: A prospective study
Harish M Rajegowda, Deepadarshan Kalegowda, Shashikumar B Madegowda, Ambika C Rangarajaiah
Department of Dermatology, Venereology and Leprosy, Mandya Institute of Medical Sciences, Mandya, Karnataka, India
|Date of Submission||16-Feb-2020|
|Date of Decision||03-Jun-2020|
|Date of Acceptance||06-Jun-2020|
|Date of Web Publication||19-Feb-2021|
Assistant Professor, Department of Dermatology, Venereology and Leprosy, #13, OPD Block, Mandya Institute of Medical Sciences, Mandya - 571 401, Karnataka
Source of Support: None, Conflict of Interest: None
Background: Idiopathic guttate hypomelanosis (IGH) is a common, acquired dermatosis characterized by multiple, round or oval, hypopigmented to depigmented macules. A variety of therapies with variable success are described, despite that, the treatment remains still unsatisfactory and a therapeutic challenge for the treating specialist. Objective: The objective of this study is to compare the safety and efficacy of 88% phenol application and cryotherapy in repigmentation of IGH macules. Materials and Methods: A total of 30 patients with more than 10 IGH macules were selected. For each enrolled patient, 88% phenol was applied to 5 IGH macules and single cryotherapy for 3–5 s was applied for another 5 IGH macules once in a month till the repigmentation for maximum of 3 applications. Patients were assessed monthly for 3 months for the side effects and improvement in pigmentation. The degree of improvement in pigmentation was assessed using a grading system, <25% - no response (Grade-1), 26%–50% - minimal (Grade-2), 51%–75% - good (Grade-3), and >75% - excellent response (Grade-4). Results: A total of 25 patients completed the study. At the end of the treatment period, out of 125 macules treated with short contact cryotherapy 75 (60%) macules showed excellent response and 20 (16%) macules showed good response. In phenol group, out of 125 macules 37 (29.6%) and 29 (23.2%) macules showed excellent and good improvement in pigmentation respectively, with P < 0.05. Side effects such as persistent scabbing, ulceration were more common with 88% phenol application compared to cryotherapy. Conclusion: Short contact cryotherapy of 3–5 s was found to be more efficacious and safe compared to therapeutic wounding with 88% phenol in inducing pigmentation of IGH macules.
Keywords: 88% phenol, cryotherapy, idiopathic guttate hypomelanosis
|How to cite this article:|
Rajegowda HM, Kalegowda D, Madegowda SB, Rangarajaiah AC. Efficacy and safety of 88% phenol application versus cryotherapy in repigmentation of idiopathic guttate hypomelanosis: A prospective study. Clin Dermatol Rev 2021;5:49-53
|How to cite this URL:|
Rajegowda HM, Kalegowda D, Madegowda SB, Rangarajaiah AC. Efficacy and safety of 88% phenol application versus cryotherapy in repigmentation of idiopathic guttate hypomelanosis: A prospective study. Clin Dermatol Rev [serial online] 2021 [cited 2022 Jan 27];5:49-53. Available from: https://www.cdriadvlkn.org/text.asp?2021/5/1/49/309767
| Introduction|| |
Idiopathic guttate hypomelanosis (IGH) is a acquired benign dermatosis of skin characterized by numerous, round to oval macules which are hypopigmented to depigmented in nature. The macules appear in descending order of frequency in upper and lower extremities, trunk, and face. Usually, the total number increases with time, whereas the size remains unchanged.
Sunlight has been long incriminated in the pathogenesis of IGH because lesions are mainly located at sun exposed body areas. The histological findings associated with IGH are hyperkeratosis, rarely an atrophic epidermis and flattened rete ridges. In addition, a decreased melanin content and reduced numbers of melanocytes are reported features.
A variety of therapies with variable success are described, including cryotherapy, superficial abrasion, topical steroids, therapeutic wounding with 88% phenol, topical retinoids, and topical pimecrolimus. Despite several therapeutic modalities, the treatment of IGH still remains unsatisfactory and therapeutic challenge for the treating specialist.
The aim of our study is to compare the safety and efficacy of cryotherapy versus 88% phenol application for repigmentation of IGH macules.
| Materials and Methods|| |
A prospective comparative study was conducted after obtaining the ethical committee clearance for 1 year between June 2017 and May 2018. Patients were enrolled for the study after obtaining the written informed consent. Detailed history and clinical examination were carried out to know the type, distribution, and number of lesions. A total of 30 patients with Fitzpatrick skin Type IV and V between the age group of 18 and 70 years, with more than 10 IGH macules were included in the study. Macules with similar clinical characteristics (size, shape, color, and distribution) were identified and five macules were allocated into each group. Patients who were severely ill and debilitated, with known cardiac problems, active infections, keloidal tendencies, active vitiligo, cold intolerance, pregnant, and lactating women were excluded from the study.
For each enrolled patient, 88% phenol was applied with cotton tip applicator to 5 IGH macules once in a month till the repigmentation for maximum of 3 applications and single cryotherapy for 3–5 s, using liquid nitrogen spray gun was applied for another 5 IGH macules once in a month till the repigmentation for maximum 3 applications. A total of 250 macules (125 in each group) were assessed.
The Phenol (<0.5 ml at each sitting) was applied with a cotton tip applicator to cover the entire macule and feathering of the border done to cover 1 mm of surrounding normal skin. The appearance of uniform white frost (20–30 s) considered as primary end point. Pulse and blood pressures of the patients were monitored before and after the application of phenol because of its cardiac toxicity. All the patients were advised to apply topical 2% mupirocin ointment, twice daily for 1 week. Patients were assessed monthly and followed up for 3 months for the side effects and improvement in pigmentation.
In each session, cryotherapy was given in one cycle for 3–5 s using liquid nitrogen cryo spray gun with nozzle size of 0.5 mm.
The degree of improvement in pigmentation was assessed in each macule using a grading system, <25% - no response, 26%–50% - minimal, 51%–75% - good, and >75% - excellent response.
The data were entered and analyzed with the help of the SPSS version 20 (IBM Company, Chicago) software. Data were expressed as mean ± standard deviation for quantitative variables, and number and percentage for qualitative ones. Chi-square test and t-test were used wherever appropriate. P < 0.05 was considered statistically significant.
| Results|| |
A total of 30 patients (18 males, 12 females M: F: 1:0.6) with mean age of 56.5 ± 12.87 years (range: 30–70 years) were included in this comparative study. Twenty-five patients completed the study. Ten macules in each patient, a total of 250 macules were assessed. Eighty-eight percent phenol was applied for 125 macules (5 in each patient) and short contact cryotherapy was applied for remaining 125 macules (5 in each patient). Classical hypopigmented macule over sun damaged skin was the common (74%) clinical type in our study. The common site of distribution of IGH macules in our study was shin (70%), followed by forearm (46.6%) and trunk (26.6%). Most of the individuals had more than 2 sites involvement.
Among the phenol applied 125 macules, 96 (76.8%) macules showed improvement in pigmentation, 29 (23.2%) macules had no response. Of the 125 macules treated with cryotherapy, 110 (88%) macules showed signs of repigmentation, 15 (12%) macules showed no repigmentation. In phenol group, of 125 macules 37 (29.6%) and 29 (23.2%) macules showed excellent [Figure 1]a and [Figure 1]b and good improvement in pigmentation, respectively. In cryotherapy applied group, 75 (60%) macules showed excellent improvement [Figure 2]a and [Figure 1]b and 20 (16%) macules showed good improvement in pigmentation. P < 0.05 which is statistically significant [Table 1] and [Graph 1]. Signs of repigmentation noted in each macule at the end of 4 weeks in phenol group and 6–8 weeks in cryotherapy group. Five patients in phenol group and eight patients in cryotherapy group required 2nd application. None of the macules in both the groups showed reappearance in depigmentation at the end of 3 months' follow up. [Table 2] summarizes the treatment response at each visit.
|Figure 1: Excellent response (>75%) with 88% phenol application (a) before (b) after|
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|Figure 2: Excellent response (>75%) with short contact cryotherapy (a) before (b) after|
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|Table 2: Summary of therapeutic response in treatment groups at each visit|
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Side effects such as persistent scabbing (scab which persisted for >15 days) [Figure 3], scarring [Figure 4] and postinflammatory hyperpigmentation [Figure 5] were common with phenol group compared to cryotherapy group [Table 3].
|Figure 5: Postinflammatory hyperpigmentation following phenol application|
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| Discussion|| |
IGH is a benign dermatosis of skin, first described in 1951 by Costa as “symmetric progressive leukopathy of the extremities.” Cummings and Cottel introduced the term IGH in clinical practice in 1966 and confirmed its incidence in large group of population. The exact etiopathogenesis of IGH is still unknown. Hereditary and environmental factors play a role in the pathogenesis. The occurrence of IGH macules in post renal transplant patients associated positively with HLA-DQ3. Sunlight had been incriminated in the pathogenesis because the IGH macules predominantly distributed in the sun exposed areas. Repeated trauma also acts as a precipitating factor for the development of IGH. The exact mechanism of depigmentation in IGH is not known, possible mechanism is the functional abnormalities in the lesional melanocytes.
There are three morphological variants of IGH. The typical lesion is a hypopigmented macule (or multiple macules) in a background of sun-damaged skin, in an exposed area. The second type is an ivory white, stellate, well demarcated, sclerotic macule unrelated to sun exposure. The third type is a hypopigmented, well-demarcated small lesion with a keratotic flat crust; this type often has a scalloped border. The dermoscopic study of IGH lesions reveals the existence of normally pigmented specks scattered within the macules and perimetric pigmentary extensions. IGH may be developed according to four patterns, which are nebuloid, petaloid, amoeboid, and feathery.
Various treatment modalities are available for the management of IGH; including cryotherapy, superficial abrasion, topical steroids, therapeutic wounding with 88% phenol, topical retinoids, topical calcineurin inhibitors, and fractional CO2 LASERS.
The postulated mechanism of repigmentation following therapeutic wounding with 88% phenol is that, during the process of wound healing inflammatory process stimulates follicular and perilesional melanocytes through the liberation of cytokines to induce pigmentation. Exact mechanism of repigmentation following cryotherapy is still unknown.
Postulated factors includes, freezing inactivates inhibitory enzymes and chemokines to allow the repigmentation to occur. Second possibility is that destruction of overlying keratinocytes inhibit the negative effect of keratinocytes on melanocytes. Third, following cryotherapy post inflammatory hyperpigmentation may be responsible for repigmentation.
Ravikiran et al., in their study reported 64% of the IGH macules showed repigmentation with 88% phenol spot peel compared to our study 76.8% macules showed repigmentation.
Ploysangam et al., in their study reported 90.8% of the treated lesions were repigmented 6–8 weeks after being gently frozen with liquid nitrogen, which was applied with a cryoprobe for 10 s. Kumarasinghe, in his study reported 100% improvement in pigmentation of the macules using a liquid nitrogen spray gun for 3–5 s. Falabella et al., in their study reported 50% improvement in repigmentation of IGH macules using intralesional steroids along with skin grafting. Shin et al., in their study reported 47.9% patients showed >75% improvement with single session fractional CO2LASER.
In our study, 88% macules showed signs of repigmentation with short contact cryotherapy using liquid nitrogen spray gun. Further studies with longer duration of follow-up required to confirm our results.
To the best of our knowledge, this is the first comparative study between cryotherapy and phenol application in repigmentation of IGH macules.
| Conclusion|| |
Disorders of pigmentation affect a large proportion of the population, causing great concern not only for human health, but also for the induced social implications. Short contact 3–5 s cryotherapy with liquid nitrogen spray is simple, more efficacious and safe compare to 88% phenol application.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2], [Table 3]