Conventional and Novel Treatment Strategies for Porokeratoses: A Narrative Review.

Porokeratoses are a heterogenous group of autoinflammatory keratinization disorders all characterized by the presence of a cornoid lamella. In addition to gene mutations affecting the mevalonate pathway, environmental factors such as UV radiation, immunosuppression, trauma, and infection are also thought to contribute to porokeratoses. To date, there are no management guidelines or levels of evidence for commonly used pharmacologic and non-pharmacologic treatment options for porokeratoses. Conventional treatment strategies encompass topical and systemic drugs (e.g., salicylic acid, topical glucocorticoids, and retinoids), phototherapy, laser, and surgical interventions. Better insights into the pathogenesis of porokeratoses have paved the way for the development of novel therapeutic approaches, such as topical statins or the use of monoclonal antibodies. This narrative review aims to summarize both conventional and novel treatment options, including their level of evidence, advantages, and disadvantages.

Porokeratosis on the lip: A Case Series.

Porokeratosis is a skin condition that involves the formation of plaques, characterized by a hyperkeratotic ridge with an atrophic center. There is a histological presence of a cornoid lamella, which is a parakeratotic column that traverses through the stratum corneum. The plaques are mostly benign but have the potential to become squamous cell carcinomas if left untreated. Porokeratosis lesions typically occur on the extremities, but they can develop anywhere. The occurrence of porokeratosis on the lip is exceedingly rare. We report three cases of porokeratosis on the lip. Each incidence was treated with cryotherapy, which was unsuccessful in two. One of these two patients did not elect for topical treatment and is being monitored for lesion changes. The second patient was successfully treated via shave biopsy. The third patient was lost to follow-up post-cryotherapy.

Mosaic GJB2 mutations in widespread porokeratotic adnexal ostial nevus: Report of two patients.

Porokeratotic adnexal ostial nevus (PAON) is a rare adnexal hamartoma characterized by keratotic papules following Blaschko's lines, typically located on the unilateral distal extremities. Cutaneous somatic GJB2 mutations have been linked to the pathogenesis of PAON. However, the genetic mechanism underlying bilateral or extended forms, which are less documented, remains unknown. In this study, we presented two cases of PAON with widespread cutaneous lesions and scalp involvement, and demonstrated the presence of GJB2 mosaic mutations in both patients. We further investigated the mosaic frequency in different tissues to gain insights into the mutation events contributing to the phenotype of widespread PAON. Our findings suggest that early postzygotic mutation causing mosaic GJB2 mutations may contribute to the widespread phenotype of PAON, thereby enriching the disease spectrum and mutation profile of PAON.

Cutaneous Horn Presentation in Porokeratotic Eccrine Ostial and Dermal Duct Nevus. A Brief Review and Case Report.

ABSTRACT: Porokeratotic eccrine ostial and dermal duct nevus is a rare adnexal hamartoma characterized by the presence of a cornoid lamella exclusively overlying eccrine acrosyringia. Different clinical presentations have been reported in the literature. Here, we report a case of a 6-year-old girl diagnosed with porokeratotic eccrine ostial and dermal duct nevus confirmed by histopathologic study. Atypical lesions are described as whitish, warty-looking neoformations located in the anterolateral region of the right hip (cutaneous horn).

Efficacy of Topical Cholesterol and Statin Combination Therapy in the Treatment of Porokeratosis: A Systematic Review and Meta-Analysis.

BACKGROUND: Porokeratosis is a group of disorders characterized by aberrant skin keratinization secondary to genetic alterations in the mevalonate pathway, which participates in cholesterol synthesis. While a rare disorder, malignant transformation to squamous cell carcinoma is seen in up to 11% of cases. Recently, topical cholesterol and topical statin therapy have been suggested as a pathogenesis-directed treatment for porokeratosis. METHODS: A PubMed/MEDLINE and Embase literature search was performed using the search terms: "porokeratosis" AND "cholesterol" OR "lovastatin" OR "simvastatin" OR "atorvastatin" OR "fluvastatin" OR "pitavastatin" OR "pravastatin" OR "rosuvastatin" OR "statin." Peer-reviewed clinical trials, case series, and case reports of all porokeratosis subtypes were included. RESULTS: Eleven articles were included in the systematic review and 9 articles in the meta-analysis. The systematic review consisted of an aggregate of 33 patients, most of whom (n=31, 93.9%) applied the treatment twice daily for an average of 9.4 weeks (median=8 weeks), with 93.9% (n=31) experiencing improvement or resolution of porokeratosis. Sixteen patients (48.5%) used lovastatin and 16 (48.5%) used simvastatin with concurrent cholesterol therapy. Mild adverse events including erythema and contact dermatitis were experienced by 12.1% of patients. Our meta-analysis yielded a random effects model supporting a robust reduction in porokeratosis severity (OR = .076, 95% CI [0.022, 0.262]). CONCLUSION: This underpowered meta-analysis provides limited, preliminary evidence supporting the efficacy of topical cholesterol/statin therapy. Overall, quality studies and aggregated sample size are limited; future large clinical trials are needed to further elucidate the role of topical cholesterol/statin therapy in the treatment of porokeratosis. J Drugs Dermatol. 2023;22(12):1160-1165. doi:10.36849/JDD.7775.

A Review of the Efficacy of Topical Statins for Treating Disseminated Superficial Actinic Porokeratosis.

Porokeratosis is a rare group of acquired or hereditary dermatoses characterized by linear or annular plaques with a keratotic border. DSAP is the most common porokeratosis, and lesions range from asymptomatic to pruritic circular pink to brown macules, papules, or plaques surrounded by a raised border. DSAP carries about 7.5-10% risk of malignant transformation to SCC or BCC. While in the past DSAP has been widely treated with topical diclofenac, ingenol mebutate, topical vitamin D analog, 5-fluorouracil, imiquimod, photodynamic therapy, retinoids, cryotherapy, and laser therapy, these therapies have shown limited efficacy and have caused adverse effects including inflammatory reactions, hyperpigmentation, pain, and erythema. Recently, a formulation of topical statin and cholesterol has surfaced as a new and promising treatment for DSAP which has shown clinical improvement with a tolerable adverse effect profile when compared to the current therapies. Of the 8 case studies with a total of 20 patients with DSAP, 90% (18/20) reported clinical improvement with various forms of topical statin therapy. While promising, larger randomized controlled trials are needed to evaluate the long-term use of topical statins for DSAP. J Drugs Dermatol. 2023;22(10):     doi:10.36849/JDD.7540.

Treatment of Porokeratosis Ptychotropica With a Topical Combination of Cholesterol and Simvastatin.

This case report describes 2 patients with Ptychotropic porokeratosis who were treated with a combination of cholesterol and simvastatin.

Disseminated superficial actinic porokeratosis following hydroxyurea treatment: A case report.

Porokeratosis encompass a group of acquired and familial, preneoplastic, keratinization disorders, clinically characterized by atrophic macules or patches with a peripheral keratotic rim, the cornoid lamella. Genetic background is recognized as crucial in its pathophysiology, while immunosuppression and ultraviolet radiation represent triggering factors. We report the case of a woman who developed disseminate superficial actinic porokeratosis following the intake of hydroxyurea for a polycythaemia vera. Clinical, dermoscopic and histopathology data are showed, and the role of drug as a second-hit mutation trigger is discussed.

Porokeratosis is one of the most common genodermatoses and is associated with an increased risk of keratinocyte cancer and melanoma.

BACKGROUND: Porokeratosis is a clinically heterogeneous group of keratinization disorders with a genetic background mainly affecting the mevalonate pathway, which is involved in the synthesis of cholesterol, an essential component for the formation of the extracellular lipid lamellae in the stratum corneum. Porokeratosis is reportedly associated with an increased risk of keratinocyte cancer, but to date, no large epidemiological studies have been conducted to further address this association. OBJECTIVES: The first objective was to characterize a cohort of patients diagnosed with porokeratosis at the Department of Dermatology and Venereology, Sahlgrenska University Hospital (SU), Gothenburg, Sweden. The second objective was to conduct a nationwide registry-based cohort study to investigate the association, if any, between porokeratosis and the cutaneous malignancies squamous cell carcinoma (SCC), basal cell carcinoma (BCC) and melanoma. METHODS: For the SU cohort, the hospital registry was searched for patients with a diagnosis of porokeratosis recorded between 2016 and 2020. Clinical data were extracted from the records of the identified patients. For the nationwide cohort, national registries were searched to identify patients with a diagnosis of porokeratosis between 2001 and 2020. A tenfold control cohort was formed by Statistics Sweden. The data was cross-referenced with the Swedish Cancer Register to study the associations between porokeratosis and SCC, BCC and melanoma. RESULTS: Disseminated superficial actinic porokeratosis was the most common clinical type among the 108 patients in the SU cohort. In the nationwide search, 2277 patients with porokeratosis were identified (prevalence 1/4132). Porokeratosis was associated with an increased risk for SCC, BCC and melanoma with hazard ratios (95% CI) of 4.3 (3.4-5.4), 2.42 (1.97-2.98) and 1.83 (1.18-2.82), respectively, in the patient cohort, compared to the matched control group. CONCLUSION: Porokeratosis is a common genodermatosis, and it is associated with an enhanced risk of skin cancer.

A possible role for second-hit postzygotic GJB2 mutation in porokeratotic eccrine ostial and dermal duct nevus.

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is a rare type of epidermal nevus involving the eccrine acrosyringia. It typically presents as asymptomatic linear keratotic papules and plaques along the lines of Blaschko and predominantly affects the extremities. This disease has recently been linked to somatic mutations within the GJB2 locus. Only four GJB2 mutations have been previously documented for PEODDN, and the underlying genetic basis remains inconclusive. Herein, we report an 18-year-old female with a hyperkeratotic plaque on the dorsa of the proximal interphalangeal joint of her right ring finger, as well as multiple small hyperkeratotic papules linearly distributed on the lateral sides of her fingers occurring since birth. Histopathological results revealed prominent parakeratotic cornoid lamella-like tiers at the opening of the eccrine secretory ducts. Whole-exome sequencing of the affected skin tissue revealed a heterozygous germline mutation and a postzygotic somatic mutation in GJB2. In summary, this study presents a case of PEODDN with compound heterozygous mutations in GJB2, which broadens the genetic spectrum of this disease entity and implies a possible role for second-hit mutations in the pathogenesis of PEODDN.

Porokeratotic Variant of Lichen Planus.

A 44-year-old woman presented with mildly itchy, brownish-black plaques for the last 2 years. The lesions first appeared on the upper back, followed by involvement of the face and upper arms within 4-5 months. Individual lesions began as small papules that gradually evolved into small, annular, and barely palpable plaques. There were no systemic complaints, photosensitivity, or history of intake of prolonged medication. Cutaneous examination revealed multiple, well-demarcated, and hyperpigmented oval to round plaques on the photo-exposed area, including the face, bilaterally on arms, and upper trunk, measuring about 1 × 1-3 × 3 cm2 in size (Figures 1A and 1B). Dermatoscopic examination established rolled-out, thread, double-marginated border with central atrophy with a brownish reticular background. Multiple brownish to black globules and dark lacunae were also observed (Figures 1C and 1D). No Wickham's striae were viewed. Combination of clinical presentation with dermatoscopic findings indicated a provisional clinical diagnosis of disseminated superficial porokeratosis. Biopsy performed on the upper back revealed hyperkeratotic epidermis with mild lymphocytic exocytosis and spongiosis with pigmentary incontinence. The coronoid lamina was not revealed in any of the pathologic sections examined, including further deeper sections and in a repeat biopsy. Clinical morphology, dermatoscopic features, and pathology were considered compatible with the diagnosis of porokeratotic variant of lichen planus (LP). The patient was counseled and started on topical steroids (fluticasone). She is on regular follow-up.