|Year : 2022 | Volume
| Issue : 1 | Page : 1-5
Efficacy and safety of 10,600 nm fractional carbon dioxide laser versus 88% phenol in treatment of idiopathic guttate hypomelanosis: A prospective study
K Deepadarshan, MR Harish, BM Shashikumar, Priyanka R Chandran
Department of Dermatology, Mandya Institute of Medical Sciences, Mandya, Karnataka, India
|Date of Submission||23-Mar-2022|
|Date of Acceptance||11-May-2022|
|Date of Web Publication||30-Jun-2022|
Dr. K Deepadarshan
Department of Dermatology, Mandya Institute of Medical Sciences, Nehrunagar, Mandya - 571 401, Karnataka
Source of Support: None, Conflict of Interest: None
Background: Idiopathic guttate hypomelanosis (IGH) is a common benign acquired leukodermic dermatosis characterized by multiple, discrete, hypopigmented-to-depigmented macules. Various treatment modalities were tried for this condition with varied results. Purpose: This study was conducted to compare the efficacy and safety of fractional carbon dioxide laser and 88% phenol in the treatment of IGH. Methods: A total of 40 patients with five IGH macules on each side were treated with one session of fractional carbon dioxide laser on the right side and a single application of 88% phenol on the left side and were assessed monthly for 3 months. The improvement in pigmentation was graded as ≤25% - poor, 26%–50% - minimal, 51%–75% - good, and >75% - excellent response. Results: A total of 32 patients completed the study. Out of the 160 macules treated with laser, 16 (10%) macules showed an excellent response and 40 (25%) showed a good response, and 40 (25%) and 48 (30%) macules in the phenol group showed excellent and good improvement, respectively. Side effects such as persistent scabbing and ulceration were seen only on the phenol side. Conclusion: Single application of 88% phenol was more efficacious than one session of fractional carbon dioxide laser in inducing pigmentation in IGH macules in this study. However, fractional carbon dioxide laser can be considered a safer alternative modality.
Keywords: 88% phenol, fractional carbon dioxide laser, idiopathic guttate hypomelanosis
|How to cite this article:|
Deepadarshan K, Harish M R, Shashikumar B M, Chandran PR. Efficacy and safety of 10,600 nm fractional carbon dioxide laser versus 88% phenol in treatment of idiopathic guttate hypomelanosis: A prospective study. J Dermatol Dermatol Surg 2022;26:1-5
|How to cite this URL:|
Deepadarshan K, Harish M R, Shashikumar B M, Chandran PR. Efficacy and safety of 10,600 nm fractional carbon dioxide laser versus 88% phenol in treatment of idiopathic guttate hypomelanosis: A prospective study. J Dermatol Dermatol Surg [serial online] 2022 [cited 2022 Aug 18];26:1-5. Available from: https://www.jddsjournal.org/text.asp?2022/26/1/1/349429
| Introduction|| |
Idiopathic guttate hypomelanosis (IGH) is a common benign acquired pigmentary disorder of unknown etiology usually affecting the elderly population clinically characterized by multiple, discrete, asymptomatic round-to-oval, hypopigmented-to-depigmented, and porcelain-white macules ranging from 0.2 cm to 2 cm mostly on the sun-exposed areas.,,
Treatment for IGH is difﬁcult; however, studies have reported successful treatment with modalities such as topical pimecrolimus, tacrolimus, tretinoin, cryotherapy, 88% phenol, nonablative fractional photothermolysis, fractional carbon dioxide laser, and excimer laser.,,,,,, The purpose of this study is to compare the efficacy and safety of fractional carbon dioxide laser and 88% phenol in the treatment of IGH.
| Methods|| |
Forty patients with IGH satisfying the inclusion criteria of having more than ten IGH macules, at least five on each half of the body, aged between 18 and 60 years, with no previous treatment with topical medication, phototherapy, cryotherapy, or laser modalities during the past 6 months were considered for the study after obtaining informed written consent. Pregnant and lactating women, patients with active infection, bleeding disorders, preexisting cardiac disease, dermatosis that is exacerbated by ultraviolet (UV) radiation, on medications known to have potential phototoxic reactions, history of hypertrophic scars or keloids, and known history of vitiligo were excluded from the study.
The study was conducted over 7 months from May 2021 to November 2021, in the outpatient department of dermatology at our institute, after obtaining ethical committee clearance from the Institutional Review Board.
The patient's demographic data and relevant history were taken at baseline. A thorough cutaneous examination was performed, five IGH macules on each side of the body were selected, and appropriate digital photographs were taken. IGH lesions over the right half were treated with one session of 10,600 nm fractional carbon dioxide laser and lesions over the left half were treated with one application of 88% phenol.
In each patient, five IGH macules on each side were selected, marked, and photographs were taken before the procedure. Topical anesthetic cream (eutectic mixture of 2.5% lidocaine and 2.5% prilocaine) was applied under occlusion for 45 min for macules over the right side which was then treated with one session of 10,600 nm fractional carbon dioxide laser (Futura RF 40) with a power of 25W, 100 mJ point energy, the density of 0.8 mm, single-pass in normal scan mode.
Macules over the left side were treated with a single application of 88% phenol applied with a cotton-tipped applicator [Figure 1]. Phenol was taken in a container and using an applicator, it was applied to cover the entire lesion and also 1 mm of surrounding normal skin. The endpoint of treatment was the appearance of uniform white frosting [Figure 2]. The pulse rate and blood pressure of the patients were monitored before and after the procedure due to the risk of cardiac toxicity associated with phenol. All the patients were advised to apply topical 2% mupirocin ointment twice daily for 5‒7 days.
Patients were evaluated both clinically and by comparing with the baseline photograph every month for a total of 3 months to assess the improvement in pigmentation of IGH macules and also any immediate or late adverse effects; if any are recorded. Clinical photographs were taken at baseline, 4 weeks, 8 weeks, and 12 weeks. Patients were assessed by serial photographic evaluation under standardized conditions of lighting, patient position, and camera equipment. The degree of clinical improvement was graded according to the investigator's Global Assessment Scale using a quartile grading system as follows:
- Grade 1: ≤25%: poor response
- Grade 2: 26%–50%: minimal response
- Grade 3: 51%–75%: good response
- Grade 4: >75%: excellent response.
Patients were also observed for side effects of lasers and phenol such as erythema, burning sensation, postinflammatory hyperpigmentation, persistent scabbing, and ulceration.
Data were analyzed using the SPSS software version 20, IBM Company, Chicago. Simple statistical tests such as mean, median, and standard deviation (SD), and also descriptive and analytical statistical tests were performed. Chi-square test and t-test were used to compare the efficacy of two treatment modalities and P < 0.05 was considered statistically significant.
| Results|| |
A total of 40 patients were recruited for the study of which 24 were male and 16 were female (M:F = 1.5:1) with ages ranging from 36 to 60 years with a mean age of 48.85 and SD of 6.24 years. The duration of IGH ranged from 6 months to >6 years in our study. The majority of the patients (85%) had an insidious onset of the condition with no associated itching or exacerbation of the lesions on sun exposure. The common sites of distribution of IGH macules in our study were the lower extremity, followed by the upper extremity and trunk with relative sparing of the face and neck with a majority (75%) of them having multiple sites of involvement.
A single application of 88% phenol and one session of fractional carbon dioxide laser treatment were provided to all 40 patients enrolled in the study. However, only 32 patients completed the study. A total of 320 macules were assessed, 10 macules in each patient. Out of the 160 macules treated with fractional carbon dioxide laser, 16 (10%) macules showed excellent improvement - >75% [Figure 3], 40 (25%) macules showed a good response - 51%–75%, minimal response - 26%–50% was shown by 56 (35%) macules, and 48 (30%) macules showed poor response - ≤25%. In the phenol group, out of the 160 macules, 40 (25%) macules showed excellent improvement [Figure 4], 48 (30%) macules showed good improvement, 44 (27.5%) showed a minimal response, and 28 (17.5%) showed poor response [Graph 1]. The summary of treatment response at each follow-up visit is depicted in [Table 1].
|Table 1: Summary of therapeutic response in treatment groups at each visit|
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|Figure 3: Excellent response (>75%) with fractional CO2 laser (a) before and (b) after|
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|Figure 4: Excellent response (>75%) with 88% phenol application (a) before and (b) after|
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Each macule had individual variation in the degree of pigmentation. On both sides, repigmentation was noted by around 4–8 weeks. None of the repigmented macules showed reappearance of depigmentation at the end of the 3-month follow-up period. After the end of the study period, another session of fractional carbon dioxide laser treatment was provided for 20 out of the 48 macules which showed a poor response with a single-treatment session, and 12 (60%) out of the 20 macules showed excellent response suggesting fractional carbon dioxide laser is an effective modality but requires more than one session to achieve complete repigmentation. However, those results were not included in our present study.
Side effects such as burning sensation, erythema [Figure 5], persistent scabbing [Figure 6] for more than 15 days, postinflammatory hyperpigmentation, and ulceration were noted in the phenol group. However, on the side treated with fractional carbon dioxide laser, none of the patients reported any side effects immediately following the treatment or in the subsequent visits.
| Discussion|| |
IGH is a common, acquired, benign leukodermic dermatosis of the skin usually affecting the elderly population. This condition was ﬁrst described by Costa in 1951 as “symmetric progressive leukopathy of the extremities.”,, The probability of acquiring IGH increases with age, ranging from 47% in the age group of 31–40 years to 97% in 81–90 years. The exact etiopathogenesis of IGH is not fully understood. Genetic and environmental factors may play a role in its pathogenesis. In postrenal transplant patients, there was a statistically significant increase in the incidence of IGH with the HLA-DQ3 haplotype; and a negative association in patients with the HLA-DR8 haplotype. IGH has been hypothesized to be UV-induced rather than idiopathic because the IGH macules are predominantly distributed in sun-exposed areas. Repeated trauma, photoaging, and senile degeneration have also been regarded as a causative factor for this condition.,
IGH is a benign condition and no treatment is usually necessary. However, patients with pigmented skin request treatment owing to its psychological impact. There is no universally accepted gold standard treatment for this condition. Various modalities have been tried for the management of IGH with varied success rates. Therapeutic options for treatment of IGH macules include, topical calcineurin inhibitors (1% pimecrolimus and 0.1% tacrolimus), topical retinoids (0.025% tretinoin), superficial dermabrasion, cryotherapy, topical 88% phenol, fractional CO2 laser and excimer laser.,,,,,,
The exact pathogenesis of IGH remains unknown. Some studies showed that the epidermis in IGH lesions had a significantly reduced number of melanocytes compared with perilesional normal skin, whereas others suggested structural abnormalities of melanocytes such as fewer melanosomes, attenuated dendrite branching, or a decreased tyrosinase activity to be the underlying driving factor. Therefore, hypopigmented lesions in IGH are thought to be due to decreased melanocytes or dysfunctional melanocytes.
The postulated mechanism of repigmentation following fractional CO2 laser is by ablation of epidermis, during the process of wound healing and reepithelization, the melannocytes in the hair follicles and surrounding normal skin migrate into the lesional skin and also there is release of various cytokines and growth factors that may stimulate melanogenesis.
Similarly, therapeutic wounding with 88% phenol stimulates melanocytes from the hair follicles and peripheral normal skin to migrate into the lesional skin causing repigmentation of IGH macule. Another mechanism is based on postinflammatory hyperpigmentation induced by phenol.
In a study conducted by Ravikiran et al., IGH macules were treated with two sessions of 88% phenol 1 month apart in contrast to a single session in our study and more than 75% improvement was noted in 45% of IGH macules in comparison to 25% in the present study.
Shin et al. and Goldust et al. conducted similar studies in IGH with one session of fractional carbon dioxide laser and patients were assessed after 2 months where all the subjects (100%) showed repigmentation of IGH macules in contrast to 70% of the total IGH macules in our study.,
The small sample size and short duration of follow-up were the limitations of this study requiring further studies to confirm our results. To the best of our knowledge, this is the first comparative study between fractional carbon dioxide laser and phenol application in the treatment of IGH.
| Conclusion|| |
IGH is a common pigmentary disorder that affects a large proportion of the population and can be esthetically undesirable for patients. In our study, a single application of 88% phenol was more efficacious than one session of fractional carbon dioxide laser in inducing pigmentation in IGH macules. However, fractional carbon dioxide laser can be considered an effective, convenient, and safer modality for the treatment of IGH. Hence, larger, controlled, prospective studies are needed to support our findings and to optimize fractional laser parameters, the number of treatment sessions, and treatment intervals.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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