Lactic Acid as a new therapeutic peeling agent in the treatment of lifa disease (frictional dermal melanosis).

BACKGROUND: Lifa disease (frictional dermal melanosis) is a common dermatological problem. Full strength lactic acid has been proved to be effective and safe peeling agent in the treatment of melasma.
OBJECTIVE: To assess the effectiveness and the safety of lactic acid chemical peeling in the treatment of lifa disease.
MATERIALS AND METHODS: This open label therapeutic trial was conducted in Department of Dermatology in Najaf and Baghdad Teaching Hospitals, from March 2007-October 2008. Full strength lactic acid (92%, pH 3.5) was used as a peeling agent. The treatment sessions were done every 2 weeks until the desired response was achieved (but not more than 6 sessions). The response to therapy was evaluated by objective and subjective methods. All patients were followed monthly for 3 months after the last treatment session.
RESULTS: 52 patients with typical clinical features of lifa disease were included. All patients were slim with prominent bones and low body mass index, and gave history of using the lifa (washing agent) during bathing. The number of sessions ranged from 2-6 sessions. The pigmentation was improved in all patients as revealed by objective and subjective methods, and this response was statistically highly significant. No significant side effects were recorded in all treated patients. The improvement has been sustained without any obvious relapse throughout the follow-up period.
CONCLUSION: Lactic acid peel is a new, non-costly mode of therapy in treating dermal melanosis in patients with lifa disease.

What was known?

1. Dermal melanosis is recalcitrant to many therapeutic interventions.

2. Full strength lactic acid solution has been reported to be an effective and safe therapeutic option in melasma.

Introduction

Lifa disease (frictional dermal melanosis) is a common pigmentary disfiguring problem, especially among females and usually seen in the people in the Middle Eastern and other Asian countries.[1-6] The disease most probably appears as a result of using rough washing agent during bathing.[1-5]

The etiopathogenesis of the disease is not well understood but Sharquie speculated that the basal layer of the epidermis would be squeezed between the underlying bony areas (like clavicle) and the overlying lifa (washing agent). There will be damage to the basal cell layer including melanocytes causing pigmentary incontinence[1] that may be seen as melanophages as proved by histopathological and wood's light examinations.[1-5]

The disease could be self-limited if the patients stop the use of the washing agent for a long time and might remit spontaneously.[6]

Generally, dermal melanosis is recalcitrant to many therapeutic interventions, but various modalities of therapy have been tried in the treatment like dermabrasion, which has a high risk of hyperpigmentation or hypopigmentation, cryosurgery which may cause a permanent hypopigmentation[78] and Q-Switched lasers.[9] Alpha hydroxy acids (AHAs) such as glycolic and lactic acid have been reported to be effective in treating of melasma, solar lentigines and post-inflammatory hyperpigmentation.[10-12]

Lactic acid was shown to inhibit tyrosinase enzyme activity directly, in dose-dependent manner and independent to their acidic nature.[10] Full strength lactic acid solution (92% pH 3.5) has been reported to be an effective and safe peeling agent in the treatment of melasma.[11]

Therefore, this open label therapeutic trial was done in the Department of Dermatology in Najaf and Baghdad Teaching Hospitals, during March 2007 – October 2008, to assess the efficacy and the safety of chemical peeling by using full strength lactic acid (92% pH 3.5) in the treatment of lifa disease.

The inclusion criteria were: Patients with typical lifa disease (frictional dermal melanosis) clinically, who did not receive any systemic or topical treatment for the last month before the study. The exclusion criteria were: Patients with liver, kidney, heart diseases, and patients with a tendency for keloid formation, immunosuppressed patients, or prior therapy with isotretinoin or with any drugs that can induce hyperpigmentation. Also, pregnant and lactating women were excluded.

Full-detailed history from each patient regarding: Age, sex, duration of disease, previous personal history of the disease and any previous treatment used for it.

Careful physical examination was carried out to identify the site of the lesions, color, and pattern of pigmentation, distribution, and symmetry of the lesions. Wood's lamp examination was performed for every patient, and the enhancement was determined. Laboratory studies including complete blood count (CBC), renal and liver function tests were undertaken for each patient at the baseline before therapy, after the treatment sessions, and at the end of the follow-up period. Skin biopsies were taken from 21 patients (from the worst affected site). 2 staining methods were performed to each biopsy specimen, the ordinary hematoxylin-eosin, and Congo red stain.

From each patient, formal consent was taken before the start the therapy, after full explanation about the nature of the disease, course, and the procedure of treatment, follow-up, prognosis, and the need for pre- and post-treatment photographs. Also, an ethical approval was performed by the scientific committee of the Scientific Council of Dermatology and Venereology-Iraqi Board for Medical Specializations.

All patients were photographed by a digital camera as a baseline and then every 2 weeks, in the same place with fixed illumination and distance by using a digital camera (Sony: Cyber shot with resolution 7 mega pixels, DSC-W30 still camera).

Full strength lactic acid solution of 92% concentration and pH 3.5 (from Fluka AG Company in Chemische CH-9828 Buchs, Switzerland) was applied for all lesions strictly and carefully using the standard cotton-tipped applicators. This application was preceded by degreasing with 70% alcohol.

Lactic acid solution was left for 10 minutes on the skin before washing with water. Any unusual symptoms or complications at the time of treatment were noted and recorded. No pre-medication or sedation was required. All patients underwent the lactic acid peel every 2 weeks until getting the desired response.

All patients were instructed to avoid the rubbing or friction of skin with the lifa (washing agent), and patients were asked not to try any other kind of therapy during the study period. The patients were instructed to avoid sun exposure as much as possible throughout the study, and were encouraged to use sunscreen (15% zinc oxide ointment) for the exposed-treated areas. Patients who complained from discomfort and persistent redness were given hydrocortisone 1% skin cream twice daily. All the treated patients were evaluated objectively and subjectively regarding their response to the treatment by the following methods:

Objective Methods, Which Included

Color score (Darkness score)

The darkness of the hyperpigmentation was assessed according to a special color score chart that was invented by Sharquie et al., 2005.[11] According to this score, the darkness or the color of pigmentation graded from 0-4 as follows:

Score 0: Similar to the surrounding skin color

Score 1: Light brown

Score 2: Brown

Score 3: Dark brown

Score 4: Black

Photographic assessment

Color photographs for each patient were performed at the base line, after each session of therapy and at the end of the course of treatment. Frontal, right, and left views were taken using. The photographs were assessed at the end of the study in computer view blindly by two independent, out-of-the study dermatologists, and they notified their opinions about the degree of an improvement using visual analogue scale (VAS) from 0-10.

Subjective Methods, Which Included

Patient's satisfaction

This method depends on recording the degree of patient's satisfaction regarding the improvement of pigmentation during the course of intervention and graded from 0-3 as follows:

Grade 0: Not satisfied

Grade 1: Moderately satisfied

Grade 2: Greatly but not fully satisfied

Grade 3: Fully satisfied[12]

Itching improvement

All patients were asked about the state of their itching (increased, decreased, or disappeared) at each follow-up visit.

The patients were seen regularly every 2 weeks during the treatment period; at each visit, the response for the treatment was assessed, the side effects were recorded, photographs were taken, and the darkness score for each patient was estimated. Then, the patients followed up monthly for 3 months after the last treatment sessions to look for any complications or any sign of relapse.

Statistical analysis has been done by using the EPI INFO version 3.5.1. P-value of less than 0.05 was considered significant. Paired t-test was used to compare the visual analogue scales from photographical assessment before and after the therapy. Chi-square test was used to evaluate the changes in the color score before and after treatment.

52 patients were included in this study, their ages at presentation ranged from 16-45 (27.92 ± 7.580) years. The disease duration varied between 0.5-12 (4.65 ± 3.33) years. The ages of onset of the disease ranged from 15- 38 (23.19 ± 6.31) years. The disease started between 15-29 years in 43 (82.6%) patients with a (20.95 ± 4.24) years. There were 49 (94%) female patients and 3 (6%) male patients with a female: male ratio was 16:1.

The most-commonly affected sites were: Clavicles areas in 35 (67.3%) patients, back in 22 (42%), lateral aspect of the arms in 19 (36.5%), shins in 16 (30.7%) and Adam's apple in 14 (26.9%) patients. Wood's light examination of pigmentation showed no contrast in all patients.

According to Fitzpatrick classification for skin types, 21 (40.3%) patients were type III, and 31 (59.6%) patients were type IV.

The main presenting feature in all patients was the cosmetic disfigurement. Itching was found in 38 (73%) patients; in 9 (23.6%) of them, the intensity of itching was increased with high temperature and humidity.

All patients were slim with prominent bones and low BMI. The BMI of the patients ranged from 17.5- 19.8 kg/m2 (18.21 ± 0.66), 37 (71.2%) of the patients were underweight (BMI < 18.5), and the remained 15 (28.8%) were within the lower normal level (18.5-19.9).

No history of any associated skin and systemic diseases was given by any patient. There was no history of administration of drugs, or history of topical application of medication or other chemicals. Family history of similar skin pigmentation among close relatives of the patients was positive in 9 (17.3%) patients.

Histopathological examination of the lesions showed mainly dermal melanosis in a form of melanin deposition, mostly within melanophages in the papillary dermis with negative Congo red stain for amyloid.

8 patients defaulted from the study after the first treatment session for unknown reasons, and the remaining 44 patients completed the study. All the involved sites were treated. The number of sessions for each patient ranged from 2-6 (3.86 ± 1.40) sessions. The number of sessions needed by each patient depended on the cosmetic satisfaction of the patient but not more than 6 sessions.

The response to treatment, which was evaluated objectively and subjectively, was:

Color score (darkness score)

The color score was 3 (dark brown) for all patients before the treatment. The change of color score to 2 (brown) was achieved in 14 (31.8%) patients after a mean number of session's ± SD of 2.64 ± 0.74 sessions. The change of color score to 1 (light brown) was achieved in 30 (68.1%) patients after a mean number of session's ± SD of 4.43 ± 1.27 sessions [Table 1]. This change in the color score was statistically significant (P < 0.0001).

Table 1

The changes in the color score (darkness score) before and after lactic acid peel

Photographic evaluation

Before and after, photographs for all patients were seen and evaluated by two independent dermatologists [Figures 1 and 2]. The score values for all patients in the pre-treatment and post-treatment stages are showed in [Table 2]. The mean score value before treatment was 7.23 ± 0.84 while the mean score value after treatment was 2.77 ± 0.85. This difference in the VAS before and after treatment was statistically highly significant (P value < 0.0001).

Figure 1

(a) 30 years old female patient with lifa disease affecting the upper arm, before lactic acid peel, (b) After 4 sessions (8 weeks) of peel

Figure 2

(a) 35 years old female patient with lifa disease affecting the clavicular area and side of neck, before lactic acid peel, (b) After 5 sessions (10 weeks) of peel

Table 2

Visual analogue scale before and after lactic acid peel for all treated patients

All patients had satisfied regarding the therapy, and their satisfactions graded as follows:

5 (11.4%) patients were grade 1 (partially or moderately satisfied).

35 (79.5%) patients were grade 2 (greatly satisfied).

4 (9.1%) patients were grade 3 (fully satisfied).

Itching was disappeared after the first treatment session from all treated patients with itching. This effect persisted throughout the treatment sessions and the follow-up period. Also, lactic acid improved the roughness of the lesion's surface, which is present in 7 (15.9%) patients, and the skin became smooth in all patients. The improvement that was established after the last session for each patient was sustained without any obvious relapse throughout the 3 months follow-up.

Slight erythema, stinging, and burning sensation were recorded in all treated patients at the time of application of lactic acid and improved rapidly after neutralization and washing with water. Mild erythema associated with discomfort persisted for few days after peeling in 4 treated patients (9%). Hydrocortisone cream 1% was given for them until complete disappearance of the erythema. No other side effects were reported during the treatment sessions and the follow-up period; and the laboratory investigations of all patients after the treatment sessions and at the end of the follow-up were normal.

Chemical peeling have been used in the treatment of many skin problems like aging, and pigmentary disorders like melasma, by using glycolic acid.[13]

Recently, Sharquie et al. has assessed lactic acid (92%, pH 3.5) in treatment of melasma and gave very encouraging results that was comparable to Jessner's solution.[1114] The mechanism of action is to remove the epidermis up to the papillary dermis and remodeling of the skin, which give a good cosmetic appearance.[15] Also, glycolic acid or lactic acid inhibit tyrosinase enzyme directly in a dose-dependent manner and independent to their acidic nature.[12]

Lifa disease is a common dermatological problem, causing great cosmetic disfigurement. It is a distinctive entity, firstly described in Iraq by Sharquie, in 1993.[1] It has no satisfactory topical bleaching therapy although if the patient stops the use of lifa or if he gets obese, the melanosis may disappear spontaneously but this takes long time.[6] Still many patients ask for treatment for this chronic illness. Dermabrasion or laser therapy like Q Switched ND: YAG laser could be useful as it can be seen in dermal melanosis.[9] Dermabrasion, associated with high risk of post-inflammatory hyperpigmentation and response of the hyperpigmentation to treatment with laser, are quite variable, and treatment failure are common owing to persistent pigment remaining at greater tissue depths than the lasers can reach, or from re-pigmentation by stimulated melanocytes within adnexal epithelium.[16]

The present work gave a satisfactory result by using lactic acid (92%, pH 3.5) peeling with a number of sessions 2-6 and within a time of 1-3 months although all patients with skin types III and IV.

The average number of sessions needed to achieved a color score 1 (light brown) was higher that needed to achieve a color score 2 (brown) (4.43: 2.64), therefore, the higher number of sessions associated with higher degree of improvement.

To the best of our knowledge, the lactic acid peel in the treatment of lifa disease was used for the first time by the present work.

The use of topical therapies like topical AHAs, tretinoin, and hydroquinone in the pre- and/or post-peel treatment may contribute at least partially to therapeutic effect achieved by lactic acid peel.[11] The absence of pre- or post-peel treatment in the present work indicates that the improvement among patients with lifa disease was purely due to the lactic acid peel. The itching and roughness were dramatically improved, indicating anti-pruritic and smoothening effect of lactic acid.

Therefore, lactic acid peel is a safe treatment with no important side effects like scarring. Follow-up for 3 months after peelings; showed no relapse in any patient. Still, further studies using lactic acid peeling are required to confirm the results of the present work.

In conclusion, lactic acid peel is a new effective mode of therapy in clearing dermal melanosis in patients with lifa disease.

What is new?

Full strength lactic acid solution (92% pH 3.5) is an effective and safe peeling agent in clearing dermal melanosis in patients with lifa disease.