Alternative Treatment Option for Actinic Keratosis: 5% Potassium Hydroxide (KOH)
by
,
Juan David Dufflart Ocampo
1
,
Carlos Sánchez Cárdenas
2,
Elizabeth Hernández Aguilar
1,
Verónica Fonte Ávalos
3,
María Elisa Vega Memije
1 and
Gabriela Moreno-Coutiño
2,* 1
Department of Dermatology, General Hospital “Dr. Manuel Gea Gonzalez”, Mexico City 14080, Mexico
2
Division Mycology, General Hospital “Dr. Manuel Gea Gonzalez”, Mexico City 14080, Mexico
3
Division of Dermatologic Surgery, General Hospital “Dr. Manuel Gea Gonzalez”, Mexico City 14080, Mexico
*
Author to whom correspondence should be addressed.
Dermato 2025, 5(1), 2; https://doi.org/10.3390/dermato5010002
Submission received: 24 September 2024
/
Revised: 20 December 2024
/
Accepted: 10 January 2025
/
Published: 20 January 2025
Abstract
:Background: Actinic keratoses (AKs) are epidermal neoplasms with a risk of progression to squamous cell carcinoma. Multiple therapeutic options targeting single or multiple lesions, with varying degrees of clearance, have been described. Objective: Evaluate the number of cycles of 5% potassium hydroxide (KOH) solution required for the resolution of actinic keratosis. Methods: This study was conducted on 261 AK lesions in 29 patients. A cycle of application of KOH was indicated in 28 doses with a subsequent monthly clinical and dermoscopic review for a maximum of three cycles of application. Resolution was determined dermoscopically. Results: Dermoscopic resolution was observed in 203 (77.7%) lesions, obtaining a mean number of cycles for a complete resolution of 2.4. Better results were observed in patients who received three cycles than in those who received one or two cycles (p = 0.003 and p = 0.000, respectively). The most common adverse effect was burning, followed by xerosis (69 and 21%, respectively). Conclusions: The 5% KOH solution represents a promising therapeutic option for the treatment of single lesions of actinic keratosis, with an adequate response and tolerable use profile for patients. Based on our results, we suggest the use of 5% KOH solution in AKs with Olsen clinical classification I or II.
1. Introduction
Actinic keratosis (AK), also known as senile keratosis or solar keratosis, is an intraepithelial neoplasm that is a common cause of dermatological consultation [1]. They occur in photo-exposed areas of patients with accumulated sun exposure. Some authors consider them to be premalignant skin lesions that progress to squamous cell carcinoma, while other authors categorize them as “in situ” neoplasms, since they derive from clonal DNA modifications of keratinocytes [2].
Its global prevalence is 11–25%, with variations depending on region and phototype. In the EEUA, it corresponds to one-third of dermatological consultations and is the second most frequent diagnosis, with a prevalence of up to 26%, whereas in Australia, its prevalence increases up to 60% in adults aged over 40 years old [3]. The following risk factors have been identified: age (due to greater accumulated sun damage), low phototype I or II, male sex, immunosuppression, and excessive chronic sun exposure [1,3].
They appear as macules, papules, or plaques with poorly defined limits or edges, reddish, pink, or even brown in color, and may be covered with a dry attached scale. Sometimes, they can be identified more easily by palpation than by visual inspection [2]. Olsen et al. clinically classified lesions into three grades: Grade I are slightly palpable; they are felt more than they are seen, Grade II are moderately thick, easily seen and felt, and Grade III are thick, keratotic, and visually evident [4]. This classification is mostly useful for choosing the therapeutic option.
The most common dermoscopic findings of typical AKs are erythematous or reddish pseudonetworks, dilated follicular openings, yellowish-white superficial scales, rosettes, and linear or wavy vessels [5,6]. Together, these dermoscopic findings can provide a sensitivity of up to 98% for the diagnosis of AK [7].
The probability and speed of the transition from actinic keratosis to squamous cell carcinoma (SCC) are individual, highly variable, and unpredictable, with an average risk of malignancy of 8%. Multiple data reported 0.075% per lesion/year, or up to 20% per lesion/year if the patient already has a history of SCC elsewhere. In contrast, single lesions can have regression rates of up to 53% but recurrence rates greater than 50% [8].
The 5-year survival rate for non-invasive SCC is 99%. Once the carcinoma has spread to the lymph nodes, the survival rate decreases. In addition to the risk of extension, it is important to consider local growth with tissue destruction and deformity, which also implies greater complexity of reconstruction when performing surgical treatment, increasing treatment costs and morbidity [9,10].
Regarding its treatment, the use of photoprotection against ultraviolet light, cryosurgery, topical imiquimod, and topical 5-fluorouracil (5-FU) is currently strongly recommended. In addition, photodynamic therapy and topical gel diclofenac are considered therapeutic options, either individually or in combination therapy [11], as well as the combination of 5-FU and topical calcipotriol [12].
Potassium hydroxide is a strong alkali (primary irritant) that has demonstrated effectiveness, safety, and good tolerability in the topical treatment of some skin pathologies of viral etiology, including molluscum contagiosum in children and genital warts in adults. It has been proposed to act through keratin degradation, stimulation of the inflammatory response, and both cellular and innate immunity, achieving the capacity for direct local destruction and induction of changes secondary to inflammatory modulation. It is a well-tolerated treatment, with no reported systemic adverse effects and low cost [13,14,15,16].
In studies on the treatment of viral warts in adults, the effectiveness has been found to be similar to that reported with other therapies and with fewer adverse effects. In pediatric patients, it has been used as a treatment for molluscum contagiosum using 5% and 10% KOH concentrations, with similar effectiveness. Systemic adverse effects were not observed [17,18,19].
2. Materials and Methods
We designed a quasi-experimental longitudinal study. The population included adult male and female patients with clinical and dermoscopic AK diagnosis who consulted the Dermatology Service of the General Hospital “Dr. Manuel Gea González” and agreed to participate.
Demographic data were obtained from all participants. An initial assessment was carried out using clinical and dermoscopic photographs for all lesions, and emphasis was placed on the presence or absence of the typical dermoscopic findings of AK (erythematous or reddish pseudo-red background, dilated follicular openings, yellowish-white superficial scale, rosettes, linear or wavy vessels). We excluded AK lesions in patients with a history of cancer field treatment in the last 6 months, treatment with topical or systemic steroids in the last two weeks, lesions adjacent to the eyelids, mouth, or nasal passages, or those who had a history of a predisposition to develop keloid scars.
Written consent was obtained from all patients before enrolment in the study. This study was approved by the Ethics Committee of General Hospital “Dr. Manuel Gea González” (Registry number: 06-127-2022).
2.1. Treatment Protocol
Each patient was given a 20cc amber glass bottle with 10cc of 5% KOH solution with their respective dental micro applicators (in order to standardize the dose, approximately 1/8 of a drop or one touch of the applicator per each 2 mm2 of the lesion), where 14 micro applicators were delivered for daily use. The method of application was explained and handed in writing, with the number of touches of the applicator that should be given to each lesion and with an application scheme exclusively in the actinic keratosis lesions every 12 h (morning and night) for a cycle of 14 consecutive days. The indication was to discontinue after completing the 14 days (14 days of treatment + 14 days of rest = 1 treatment cycle).
2.2. Assessment of Treatment Outcome
At each follow-up appointment, each lesion was assessed individually, identifying the presence or absence of the dermoscopic findings of AKs compared to the initial visit. Dermoscopic resolution was determined by demonstrating the absence of all typical dermoscopic findings previously seen in each particular case. If the findings persisted, a second cycle of application of 5% KOH solution was indicated again with a review after 28 days, with a maximum of three cycles per lesion.
Additionally, probable adverse effects of the therapy were investigated.
This study was completed in each patient upon achieving the dermoscopic resolution of all lesions or upon the completion of three treatment cycles.
2.3. Statistical Analysis
The data obtained during the initial assessment and after each treatment cycle were recorded in a physical data collection format, recorded in an Excel database, and subsequently exported to the IBM® version 25 SPSS® program. Continuous variables were analyzed using measures of central tendency, and categorical variables were expressed as absolute and relative frequencies. The frequencies and proportions were compared using the Chi-square test. A p-value < 0.05 was considered statistically significant.
3. Results
A total of 34 patients with 295 AK lesions agreed to participate and were prescribed treatment with 5% KOH solution. Five of the participants did not attend their follow-up visits (one after two cycles and four after the first cycle). Among the reasons they indicated for them not being able to attend the follow-up, one was complications of comorbidities. The final sample of completed follow-ups included 29 patients and 261 AK lesions.
The mean age of the participants who completed the follow-up period was 72 years old. Regarding the sex of the participants, 12 were (41.3%) male and 17 (58.6%) were female. The most frequent phototype was III in 11 patients (37.9%), followed by IV in 10 patients (34.4%). The mean number of AKs per patient was 9.2. The average diameter of the AK lesions was identified as 5.6 ± 2.5 mm. The head was the most affected topography, with 154 AKs (59%). The most prevalent Olsen classification was II, with 212 lesions (81.2%). The patients’ general characteristics are listed in Table 1.
Dermoscopic resolution was observed in 203 lesions treated with 5% KOH (77.7%) (Table 2). After the first cycle of treatment with 5% KOH, clinical resolution was observed in 25 lesions (9.8%), and dermoscopic resolution was observed in 17 lesions (6.6%), indicating a second cycle of KOH in 244 lesions. Of the lesions that underwent the second cycle of treatment with 5% KOH, clinical resolution was observed in 121 (49.59%) and dermoscopic resolution in 109 (44.67%). A third cycle of treatment was indicated for 135 lesions, of which clinical resolution was observed in 85 lesions (63%) and dermoscopic resolution in 77 lesions (57%) (Figure 1).
The cumulative frequency of the dermoscopic resolution with respect to the total number of lesions was 17, 126, and 203 lesions after the first, second, and third cycles, respectively. The cumulative percentage of lesions with dermoscopic resolution compared to the total number of lesions was 6.51%, 48.27%, and 77.77% after the first, second, and third cycles, respectively (Figure 2).
Greater dermoscopic resolution was observed in lesions that received three cycles than in those that received one or two cycles (p = 0.003 and p = 0.000, respectively) (Table 2). The average number of cycles required to obtain a dermoscopic resolution was 2.4 ± 0.6.
A cross-analysis of the Olsen classification variables with dermoscopic resolution is presented in Table 3. Dermoscopic resolution was 92.5% in Olsen I actinic keratosis (p = 0.04) and 77.4% in Olsen II actinic keratosis (p = 0.032).
A total of 56 AK lesions were identified, for which dermoscopic resolution was not achieved after treatment cycles with a 5% KOH solution. These lesions had an average diameter of 7.6 mm, 42 (75%) of the lesions were located in the extremities, and according to the Olsen clinical classification, in 7 (77.8%) of the 9 Olsen III lesions, no dermoscopic resolution was evident.
The frequency and percentage of dermoscopic findings at the baseline and after the treatment cycle are shown in Table 4. A greater change in the dermoscopic findings was observed after the first cycle when compared to the pre-treatment findings (p = 0.004).
The adverse effects reported by the patients are shown in Table 5. A higher rate of adverse effects was observed in patients during the first cycle (p = 0.003). There was no significant difference between patients who received two or three cycles in terms of the presence of adverse effects (p = 0.230), and the most frequent adverse effect was burning, followed by xerosis (69 and 21%). The adverse effects were reported as tolerable, and no patient suspended the application of the 5% KOH solution because of them.
4. Discussion
There are multiple therapeutic modalities to treat AK, directed at the lesion or to the field of cancerization, all with variable degrees of clinical cure [10].
A study carried out in Germany evaluated 73 patients with AK, and a 5% KOH solution was applied every 12 h for 14 days, with a 14-day break, performing clinical follow-up at the end of the cycle, with a new treatment cycle being determined for up to a maximum of three cycles. Total remission was achieved in 54.9% of cases, partial remission in 64%, and 46% of cases presented adverse effects; the most common were local reactions [9].
Another study was carried out in Iran, with a sample of 18 patients with a total of 148 lesions; 5% KOH solution was compared with topical 5-FU, treating half of the face with 5% KOH and the other half with 5-FU, applying both once a night for 4 weeks, with follow-up at the end of treatment. These authors found similar effectiveness rates and adverse effects between both, and the impact was significant when comparing the prices of each therapy [13].
In this quasi-experimental study, KOH solution was used as a treatment for AK in cycles of 28 doses, 1 dose every 12 h, with evaluation after each cycle (14 days) to define the requirement for a new treatment cycle. A significant sample of 261 AK lesions was included, and dermoscopic resolution was reported in 203 lesions (77.7%), a finding similar to that found in the study carried out in Germany by Reinhold et al. and the study carried out in Iran. by Salehi et al. [9,13]. In our study, dermoscopic resolution was achieved in almost half (48.7%) of the lesions after two cycles of treatment, in contrast to the previously reported resolution of up to 69.9% of lesions with two cycles of treatment [9]. Therefore, in our study, we observed greater dermoscopic healing in the lesions that received three cycles, with a statistically significant result when compared with dermoscopic resolution after the first and second cycles. The average number of cycles required to achieve a dermoscopic resolution is 2.4.
Regarding the dermoscopic findings, a significant difference was found in the absence of a white-yellow scale after the first cycle of treatment, which is attributable to the direct effect of KOH as a keratolytic [16]).
Greater dermoscopic resolution was identified in lesions located in the head with the Olsen I or II clinical classification and a lower frequency of resolution in lesions located in the extremities and with the Olsen III clinical classification.
The frequency of response to KOH solution appears to be comparable with that of other local therapies, such as cryosurgery, diclofenac gel, imiquimod, 5-FU, and photodynamic therapy, which present resolution values from 60% to 90%. A response of 76% vs. 59% for 5% KOH vs. 5-Fu in monotherapy has been reported after three months of treatment [13].
Adverse events occurred mainly when carrying out the first cycle of treatment, with local events reported as tolerable, similar to what has been mentioned in the treatment of molluscum contagiosum and viral warts [14,15]. There were no serious events such as bleeding or ulceration, and in any case, it was not necessary to suspend the treatment.
We found a lower frequency of clinical resolution lesions in the extremities. This was also a topography in which more symptoms (burning and xerosis) associated with the application of the 5% KOH solution were also reported.
So, this study has results comparable to other drugs indicated for AK, with similar clearance rates and side effects, only with the cost difference being much less in the KOH 5% group [13]. As with any other therapeutic approach, 5% KOH application does not avoid the future appearance of new lesions, and these patients must continue periodic reviews, and in the case of new lesions appearing, those must be treated accordingly.
5. Limitations
This was a single-arm study that did not allow for a direct comparison with other therapeutic modalities or placebo.
It was not possible to perform a biopsy after treatment, which is the final method for determining the histological cure of actinic keratoses.
Follow-up was not performed, and the recurrence variant was not considered. An existing bias is that the spontaneous cure of actinic keratoses has been reported; therefore, a placebo-controlled study would help avoid this bias.
6. Conclusions
The 5% potassium hydroxide (KOH) solution represents a promising therapeutic option for the treatment of single actinic keratosis lesions, with an adequate response and tolerable use profile for patients.
Based on the results of our study, we suggest the use of potassium hydroxide solution in actinic keratoses with Olsen clinical classification I or II located on the head, with an indication of up to three treatment cycles of 28 doses each.
Author Contributions
Conceptualization J.D.D.O. and G.M.-C.; methodology M.E.V.M.; software, C.S.C.; validation, V.F.Á. and C.S.C.; formal analysis; investigation, G.M.-C.; resources, E.H.A.; data curation, M.E.V.M.; writing—J.D.D.O. and G.M.-C.; writing—review and editing, G.M.-C.; visualization, E.H.A. supervision, V.F.Á. and G.M.-C.; project administration J.D.D.O. All authors have read and agreed to the published version of the manuscript.
Funding
This research received no external funding.
Institutional Review Board Statement
Written consent was obtained from all patients before enrolment in this study. This study was approved by the Ethics Committee of General Hospital “Dr. Manuel Gea González”.
Informed Consent Statement
Informed consent was obtained from all subjects involved in this study.
Conflicts of Interest
The authors declare no conflicts of interest.
References
- Navarrete-Dechent, C.; Marghoob, A.A.; Marchetti, M.A. Contemporary management of actinic keratosis. J. Dermatolog. Treat. 2021, 32, 572–574. [Google Scholar] [CrossRef] [PubMed]
- Reinehr, C.P.H.; Bakos, R.M. Actinic keratoses: Review of clinical, dermoscopic, and therapeutic aspects. An. Bras. Dermatol. 2019, 94, 637–657. [Google Scholar] [CrossRef] [PubMed]
- De Oliveira, E.C.V.; da Motta, V.R.V.; Pantoja, P.C.; Ilha, C.S.d.O.; Magalhães, R.F.; Galadari, H.; Leonardi, G.R. Actinic keratosis—Review for clinical practice. Int. J. Dermatol. 2019, 58, 400–407. [Google Scholar] [CrossRef] [PubMed]
- Olsen, E.A.; Abernethy, M.L.; Kulp-Shorten, C.; Callen, J.P.; Glazer, S.D.; Huntley, A. A double-blind, vehicle-controlled study evaluating masoprocol cream in the treatment of actinic keratoses on the head and neck. J. Am. Acad. Dermatol. 1991, 24, 738–743. [Google Scholar] [CrossRef] [PubMed]
- Roldán, M.R.; Carlos, O.B. Campo de cancerización, queratosis actínica y carcinoma espinocelular: Un modelo de progresión documentado mediante dermatoscopia y microscopía de reflectancia confocal. Dermatol. Cosmética Médica Quirúrgica 2015, 13, 240–245. [Google Scholar]
- Balcere, A. Dermatoscopy of Facial Non-Pigmented Actinic Keratosis and Intraepidermal Carcinoma. In Dermatoscopy; IntechOpen: London, UK, 2021. [Google Scholar] [CrossRef]
- Huerta-Brogeras, M.; Olmos, O.; Borbujo, J.; Hernández-Núñez, A.; Castaño, E.; Romero-Maté, A.; Martínez-Sánchez, D.; Martínez-Morán, C. Validation of dermatoscopy as a real-time noninvasive diagnostic imaging technique for actinic keratosis. Arch. Dermatol. 2012, 148, 1159–1164. [Google Scholar] [CrossRef] [PubMed]
- Dianzani, C.; Conforti, C.; Giuffrida, R.; Corneli, P.; di Meo, N.; Farinazzo, E.; Moret, A.; Magaton Rizzi, G.; Zalaudek, I. Current therapies for actinic keratosis. Int. J. Dermatol. 2020, 59, 677–684. [Google Scholar] [CrossRef] [PubMed]
- Reinhold, U.; Bai-Habelski, J.; Abeck, D.; Denfeld, R.; Dominicus, R.; Fischer, T.; Radny, P. Kaliumhydroxid-5%-Lösung bei aktinischer Keratose: Ein neuer Therapieansatz zur läsionsgerichteten Behandlung [Potassium hydroxide 5 % solution in actinic keratosis: A novel therapeutic approach in the lesion-directed treatment]. Hautarzt 2021, 72, 975–983. (In Germany) [Google Scholar] [CrossRef] [PubMed]
- Werner, R.N.; Stockfleth, E.; Connolly, S.M.; Correia, O.; Erdmann, R.; Foley, P.; Gupta, A.K.; Jacobs, A.; Kerl, H.; Lim, H.W.; et al. Evidence- and consensus-based (S3) Guidelines for the Treatment of Actinic Keratosis—International League of Dermatological Societies in cooperation with the European Dermatology Forum—Short version. J. Eur. Acad. Dermatol. Venereol. 2015, 29, 2069–2079. [Google Scholar] [CrossRef] [PubMed]
- Eisen, D.B.; Asgari, M.M.; Bennett, D.D.; Connolly, S.M.; Dellavalle, R.P.; Freeman, E.E.; Goldenberg, G.; Leffell, D.J.; Peschin, S.; Sligh, J.E.; et al. Guidelines of care for the management of actinic keratosis. J. Am. Acad. Dermatol. 2021, 85, e209–e233. [Google Scholar] [CrossRef] [PubMed]
- Cunningham, T.J.; Tabacchi, M.; Eliane, J.P.; Tuchayi, S.M.; Manivasagam, S.; Mirzaalian, H.; Turkoz, A.; Kopan, R.; Schaffer, A.; Saavedra, A.P.; et al. Randomized trial of calcipotriol combined with 5-fluorouracil for skin cancer precursor immunotherapy. J. Clin. Investig. 2017, 127, 106–116. [Google Scholar] [CrossRef] [PubMed]
- Salehi Farid, A.; Niknam, S.; Gholami, K.; Tavakolpour, S.; Teimourpour, A.; Daneshpazhooh, M.; Nili, A.; Azizpour, A.; Nasimi, M.; Mahmoudi, H. Comparing efficacy and safety of potassium hydroxide 5% solution with 5-fluorouracil cream in patients with actinic keratoses: A randomized controlled trial. J. Dermatolog. Treat. 2022, 33, 1376–1382. [Google Scholar] [CrossRef] [PubMed]
- Amargo, C.L.; Belda Junior, W.; Fagundes, L.J.; Romiti, R. A prospective, open, comparative study of 5% potassium hydroxide solution versus cryotherapy in the treatment of genital warts in men. An. Bras. Dermatol. 2014, 89, 236–240. [Google Scholar] [CrossRef] [PubMed]
- Uçmak, D.; Akkurt, M.Z.; Kacar, S.D.; Sula, B.; Arica, M. Comparative study of 5% and 2.5% potassium hydroxide solution for molluscum contagiosum in children. Cutan. Ocul. Toxicol. 2014, 33, 54–59. [Google Scholar] [CrossRef]
- Teixidó, C.; Díez, O.; Marsal, J.R.; Giner-Soriano, M.; Pera, H.; Martinez, M.; Galindo-Ortego, G.; Schoenenberger, J.A.; Real, J.; Cruz, I.; et al. Efficacy and safety of topical application of 15% and 10% potassium hydroxide for the treatment of Molluscum contagiosum. Pediatr. Dermatol. 2018, 35, 336–342. [Google Scholar] [CrossRef] [PubMed]
- Baloch, H.; Ahmed, N.; Bari, A.; Farooq, O.; Qureshi, A.A. Efficacy of 5% potassium hydroxide versus 10% potassium hydroxide solution for the treatment of molluscum contagiosum at a tertiary care hospital. Pak. Armed Forces Med. J. 2021, 71, 2135–2138. [Google Scholar] [CrossRef]
- Muzaffar, F.; Faiz, F. Comparison of 5% potassium hydroxide with 10% potassium hydroxide solution in treatment of molluscum contagiosum: A comparative study. J. Pak. Assoc. Dermatol. 2014, 24, 337–341. [Google Scholar]
- Singla, C.; Mahajan, B.B.; Kaur, T.; Malhotra, S.K.; Sharma, N. Genital molluscum contagiosum in females—Therapeutic efficacy and comparative evaluation of topical 10% and 20% potassium hydroxide. Indian J. Sex. Transm. Dis. AIDS 2018, 39, 102–106. [Google Scholar] [CrossRef] [PubMed]
Figure 1.
Clinical follow-up of actinic keratosis on the forehead of a patient after two cycles of treatment with 5% potassium hydroxide solution.
Figure 1.
Clinical follow-up of actinic keratosis on the forehead of a patient after two cycles of treatment with 5% potassium hydroxide solution.
Figure 2.
(a) Typical dermoscopic findings were observed prior to the application of 5% KOH. (b) After the first treatment cycle, a marked decrease in the white scale on the surface was observed, with a pink background and follicular openings. (c) After two cycles of treatment, no dermoscopic findings of actinic keratosis were observed.
Figure 2.
(a) Typical dermoscopic findings were observed prior to the application of 5% KOH. (b) After the first treatment cycle, a marked decrease in the white scale on the surface was observed, with a pink background and follicular openings. (c) After two cycles of treatment, no dermoscopic findings of actinic keratosis were observed.
Table 1.
General characteristics of patients with actinic keratosis and actinic keratosis lesions treated with 5% KOH solution.
Table 1.
General characteristics of patients with actinic keratosis and actinic keratosis lesions treated with 5% KOH solution.
| Population: Number of Actinic Keratosis Lesions (n) | 261 |
|---|---|
| Patients’ age (years) | 72 ± 11 |
| Patient phototype | |
| I | 1 (3.4%) |
| II | 7 (24.1%) |
| III | 11 (37.9%) |
| IV | 10 (34.5%) |
| Number of actinic keratosis per patient | 9.2 ± 11.8 |
| Lesion diameter (mm) | 5.6 ± 2.5 |
| Topography | |
| Forearm | 31 (12.1%) |
| Forehead | 60 (23.4%) |
| Hand | 64 (25%) |
| Cheek | 44 (17.2%) |
| Nose | 30 (11.7%) |
| Ear | 7 (2.7%) |
| Anterior thorax | 12 (4.7%) |
| Scalp | 8 (3.1%) |
| Olsen classification | |
| I | 40 (15.3%) |
| II | 212 (81.2%) |
| III | 9 (3.4%) |
| Complete resolution with 5% KOH | 203 (79.3%) |
| Average number of cycles for complete resolution | 2.4 ± 0.61 |
The results are presented in frequencies (%); means ± SD.
Table 2.
Treatment response of patients with actinic keratoses.
| Basal (n = 261) | After the First Cycle * (n = 261) | After the Second Cycle * (n = 244) | After the Third Cycle (n = 135) | |
|---|---|---|---|---|
| Clinical resolution | - | 25 (9.6%) | 121 (49.6%) | 85 (63%) |
| Dermoscopic resolution | - | 17 (6.5%) | 109 (44.7%) | 77 (57%) |
| Repeat KOH | - | 244 (93.5%) | 135 (55.3%) | - |
Results are presented in frequencies (%); * comparison of the number of cycles vs. dermoscopic resolution. Chi-square (cycle 1 vs. cycle 3; p = 0.003 and cycle 2 vs. cycle 3; p = 0.001).
Table 3.
Dermoscopic resolution of actinic keratoses treated with 5% KOH solution according to their clinical classification.
Table 3.
Dermoscopic resolution of actinic keratoses treated with 5% KOH solution according to their clinical classification.
| Olsen Clinical Classification | With Dermoscopic Resolution | No Dermoscopic Resolution | Total |
|---|---|---|---|
| Olsen I | 37 (92.5%) p = 0.04 | 3 (7.5%) | 40 |
| Olsen II | 164 (77.4%) p = 0.032 | 48 (22.6%) | 212 |
| Olsen III | 2 (22.2%) | 7 (77.8%) | 9 |
| Injury Count | 203 | 58 | 261 |
Results are presented in frequencies (%).
Table 4.
Presence of dermoscopic findings of actinic keratoses treated with 5% KOH solution.
| Basal (n = 261) | After the First Cycle * (n = 261) | After the Second Cycle (n = 244) | After the Third Cycle (n = 135) | |
|---|---|---|---|---|
| Yellow white scale | 226 (88.3%) | 106 (41.4%) | 46 (19.2%) 17.6 | 9 (7.1%) 3.44 |
| Red pseudonetwork | 261 (100%) | 235 (91.8%) | 126 (52.7%) 48.3 | 43 (34.1%) 16.47 |
| Follicular openings | 188 (73.4%) | 138 (53.9%) | 50 (20.9%) 19.1 | 14 (11.1%) 5.36 |
| Rosettes | 241 (94.1%) | 214 (83.6%) | 106 (44.4%) 40.6 | 38 (14.8%) 14.55 |
| Linear vessels | 208 (81.3%) | 110 (43%) | 28 (11.7%) 10.7 | 3 (1.2%) 1.14 |
Results are presented in frequencies (%); * Chi-square: p = 0.004.
Table 5.
Adverse effects reported by patients with actinic keratoses treated with 5% KOH solution.
| After the First Cycle * (n = 261) | After the Second Cycle (n = 244) | After the Third Cycle (n = 135) | |
|---|---|---|---|
| No reported effect | 73 (27.9%) | 154 (63.1%) | 83 (61.9%)) |
| Adverse effects | 186 (72.7%) | 90 (35.2%) | 45 (35.7%) |
| Ardor | 177 (69.1%) | 75 (31.38%) | 33 (26.2%) |
| Pruritus | 24 (9.4%) | 15 (6.3%) | 0 |
| Xerosis | 54 (21.1%) | 52 (21.7%) | 45 (35.7%) |
| Pain | 51 (19.9%) | 0 | 0 |
| Erythema | 22 (8.6%) | 10 (4.2%) | 0 |
| Impetiginization | 1 (0.3%) | 0 | 0 |
Results are presented in frequencies (%); * Chi-square: p = 0.002.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. |
© 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Share and Cite
MDPI and ACS Style
Dufflart Ocampo, J.D.; Sánchez Cárdenas, C.; Hernández Aguilar, E.; Fonte Ávalos, V.; Vega Memije, M.E.; Moreno-Coutiño, G. Alternative Treatment Option for Actinic Keratosis: 5% Potassium Hydroxide (KOH). Dermato 2025, 5, 2. https://doi.org/10.3390/dermato5010002
AMA Style
Dufflart Ocampo JD, Sánchez Cárdenas C, Hernández Aguilar E, Fonte Ávalos V, Vega Memije ME, Moreno-Coutiño G. Alternative Treatment Option for Actinic Keratosis: 5% Potassium Hydroxide (KOH). Dermato. 2025; 5(1):2. https://doi.org/10.3390/dermato5010002
Chicago/Turabian StyleDufflart Ocampo, Juan David, Carlos Sánchez Cárdenas, Elizabeth Hernández Aguilar, Verónica Fonte Ávalos, María Elisa Vega Memije, and Gabriela Moreno-Coutiño. 2025. "Alternative Treatment Option for Actinic Keratosis: 5% Potassium Hydroxide (KOH)" Dermato 5, no. 1: 2. https://doi.org/10.3390/dermato5010002
APA StyleDufflart Ocampo, J. D., Sánchez Cárdenas, C., Hernández Aguilar, E., Fonte Ávalos, V., Vega Memije, M. E., & Moreno-Coutiño, G. (2025). Alternative Treatment Option for Actinic Keratosis: 5% Potassium Hydroxide (KOH). Dermato, 5(1), 2. https://doi.org/10.3390/dermato5010002
