Cysteamine Isobionic-Amide Complex Versus Kligman's Formula for the Treatment of Melasma: Equal Efficacy and Rapid Onset of Action.

BACKGROUND: Modified Kligman's formula (mKF) is the gold standard treatment for melasma; however, its prolonged use is not recommended due to side effects. Cysteamine is a potent, safe, and effective depigmenting agent. Here, we conducted a double-blind, randomized, and placebo-controlled clinical trial to assess the efficacy of cysteamine isobionic-amide -- a complex with enhanced depigmenting efficacy -- and compared it to mKF for the treatment of melasma. METHODS: This study involved a total of 80 patients divided into 3 groups: cysteamine-isobionic amide, placebo, or mKF. The modified Melasma Area Severity Index (mMASI) score and spectrophotometric evaluation were conducted at baseline, week 4, week 8, and week 16. Dermatological assessment, patients’ feedback, and satisfaction including quality-of-life scores were also collected. RESULTS: At week 4, cysteamine isobionic-amide and mKF groups showed an equivalent onset of action in terms of mMASI and skin pigmentation contrast reduction. The 2 groups significantly reduced melasma severity and improved the overall skin condition with a comparable efficacy at week 16. Quality of life of melasma patients was significantly improved in the cysteamine isobionic-amide group at week 8 and further at week 16 (P<0.001) compared to the mKF group. Patients’ feedback and satisfaction were higher with the cysteamine isobionic-amide product compared to mKF. CONCLUSION: Cysteamine isobionic-amide provided a rapid onset of action and was as effective as the mKF for the treatment of melasma. The data suggest that cysteamine isobionic-amide could potentially be an acceptable alternative to mKF for the long-term treatment of melasma. J Drugs Dermatol. 2024;23(2):9-16.  doi:10.36849/JDD.7428.

Dietary habits in adult Japanese patients with vitiligo.

Vitiligo is an autoimmune skin disease with acquired depigmentation. Dietary habits may modulate the pathogenesis of vitiligo. We evaluated dietary habits in adult Japanese patients with nonsegmental vitiligo, and compared their results with those of age- and sex-matched controls. We also examined the relationship between dietary habits and Vitiligo Area Scoring Index (VASI), or vitiligo on different anatomical sites. The intakes of energy, nutrients, and foods in the participants were analyzed using a brief-type self-administered diet history questionnaire. Patients with vitiligo showed higher body mass index (BMI) and lower intakes of manganese, vitamin D, pulses, and confection, compared with controls. Multivariate logistic regression analysis showed that vitiligo was associated with high BMI. VASI was higher in males than in females, and negatively correlated with age or intakes of potatoes and vegetables other than green/yellow vegetables. Linear multivariate regression analysis showed that high VASI was associated with younger age. Multivariate logistic regression analysis showed that moderate to severe vitiligo (VASI ≥ 4.25) was associated with male sex and longer disease duration. Multivariate logistic regression analyses showed the following association with vitiligo on respective anatomical sites: high intake of eggs and dairy products and high VASI on the head or neck, high intake of oils and fats and high VASI on the trunk, high intake of cereals and high VASI on the upper limbs, male sex and high VASI on the lower limbs, and high BMI and high VASI on the hands or feet. In conclusion, the control of obesity might have prophylactic or therapeutic effects on vitiligo.

Epidermal turnover and iron metabolism in senile lentigo.

Senile lentigo (SL) is a pigmentary disorder associated with disrupted epidermal turnover. Trace minerals in the skin are known to regulate keratinocyte proliferation and differentiation. To clarify the role of iron in SL, we compared the expression of molecules related to iron metabolism between SL lesion (lesion) and the surrounding normal skin (nonlesion). Our results revealed that proteins involved in iron uptake and utilization such as transferrin receptor 1, iron regulatory protein 1, mitoferrin 1, and divalent metal transporter 1 were expressed in the lower epidermis in the nonlesion, while expression of them was also observed in the upper epidermis in the lesion. Ferroportin (FPN), involved in iron export, was expressed in the upper epidermis in the nonlesion, but was only scarcely expressed in the upper epidermis in the lesion. Hepcidin, which promotes FPN degradation, was expressed in the lower epidermis in the nonlesion; however, its expression was also observed in the upper epidermis in the lesion. These changes in the expression of molecules involved in iron uptake/export/utilization might reflect the altered iron utilization state in SL, resulting in disruption of keratinocyte differentiation and disturbing epidermal turnover. Our results suggest that the metabolism of iron in keratinocytes in SL differs from that in the normal epidermis, and these changes could be associated with the abnormal epidermal turnover and decreased melanin excretion in SL.

Dietary Fiber Inulin Improves Murine Imiquimod-Induced Psoriasis-like Dermatitis.

Psoriasis is a chronic skin disease with interleukin (IL)-17-dominated inflammation and hyperproliferation of epidermis. Dietary fiber is fermented by the gut microbiome into short-chain fatty acids (SCFAs) that manifest anti-inflammatory effects. We examined if feeding with an inulin-enriched high-fiber diet (HFD) might improve topical imiquimod-induced psoriasis-like dermatitis in mice. HFD reduced thickening and total severity scores of imiquimod-induced dermatitis and reduced epidermal thickness, inflammatory infiltrates, including Ly6G+ neutrophils, and epidermal Ki67+ proliferating cells. HFD reduced mRNA levels of IL-17A, IL-17F, IL-22, IL-1ß, tumor necrosis factor (TNF)-α, CXCL1, CXCL2, and keratin 16 and increased those of transforming growth factor (TGF)-ß1 and cyclin-dependent kinase inhibitor 1A in imiquimod-induced dermatitis. In 16S rRNA sequencing of the gut microbiome, imiquimod increased relative abundance of phylum Firmicutes, while HFD increased that of phylum Bacteroidota and genus Bacteroides. HFD increased serum and fecal concentrations of SCFA propionate. Oral propionate reduced inflammatory infiltrates and epidermal Ki67+ cells and reduced mRNA levels of IL-17A, IL-17F, IL-17C, IL-22, IL-1ß, IL-6, TNF-α, CXCL1, CCL20 and increased those of TGF-ß1and IL-10 in imiquimod-indued dermatitis. Dietary inulin supplementation improves imiquimod-induced psoriasis-like dermatitis partially via propionate, and may be a promising adjunctive therapy for psoriasis.

Clinical Guidelines for Diagnosis and Management of Peutz-Jeghers Syndrome in Children and Adults.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is a rare disease characterized by the presence of hamartomatous polyposis throughout the gastrointestinal tract, except for the esophagus, along with characteristic mucocutaneous pigmentation. It is caused by germline pathogenic variants of the STK11 gene, which exhibit an autosomal dominant mode of inheritance. Some patients with PJS develop gastrointestinal lesions in childhood and require continuous medical care until adulthood and sometimes have serious complications that significantly reduce their quality of life. Hamartomatous polyps in the small bowel may cause bleeding, intestinal obstruction, and intussusception. Novel diagnostic and therapeutic endoscopic procedures such as small-bowel capsule endoscopy and balloon-assisted enteroscopy have been developed in recent years. SUMMARY: Under these circumstances, there is growing concern about the management of PJS in Japan, and there are no practice guidelines available. To address this situation, the guideline committee was organized by the Research Group on Rare and Intractable Diseases granted by the Ministry of Health, Labour and Welfare with specialists from multiple academic societies. The present clinical guidelines explain the principles in the diagnosis and management of PJS together with four clinical questions and corresponding recommendations based on a careful review of the evidence and involved incorporating the concept of the Grading of Recommendations Assessment, Development and Evaluation system. KEY MESSAGES: Herein, we present the English version of the clinical practice guidelines of PJS to promote seamless implementation of accurate diagnosis and appropriate management of pediatric, adolescent, and adult patients with PJS.

Enhancement of Ultraviolet B-Induced Apoptosis and Elimination of DNA Damage by Pre-Irradiation with Infrared Radiation A Does Not Depend on DNA Damage Repair.

BACKGROUND: We previously reported that pre-irradiation with infrared radiation A (IRA) eliminated ultraviolet B (UVB) -induced cyclobutane pyrimidine dimers (CPDs). Accelerated elimination of CPDs could have resulted from enhanced DNA repair and/or enhanced induction of apoptosis. Using Xpa knockout (KO) mice, which are deficient in DNA repair, we examined whether IRA accelerated elimination of CPDs by enhancing DNA repair. METHODS: We have already generated mice harboring epidermal melanocytes that produce only eumelanin and dominant pheomelanin, and no melanin. To obtain such mice with impaired DNA repair ability, we backcrossed them with Xpa KO mice. Three hours before UVB irradiation, the mice were irradiated with IRA, and CPDs and apoptotic cells were examined. RESULTS: Pre-irradiation of Xpa KO mice with IRA before UVB irradiation accelerated removal of CPDs and enhanced apoptotic changes. CONCLUSION: These results indicate that enhancement of UVB-induced apoptosis and acceleration of removal of CPDs by pre-irradiation with IRA does not depend on DNA damage repair.

Five novel mutations in SASH1 contribute to lentiginous phenotypes in Japanese families.

SASH1 has been reported as a causal gene of lentiginous phenotypes with and without heredity, including an autosomal dominant type characterized by lentigines predominantly on sun-exposed areas such as the face and limbs. Recently, cases of dyschromatosis with SASH1 mutations have been reported worldwide; however, only one case has been reported from Japan. Here, we analyzed six Japanese patients who characteristically showed many lentigines on sun-exposed areas, using next-generation sequencing. We identified five novel heterozygous mutations in SASH1 (p.I586M, p.S531Y, p.R644W, p.T525R, and p.S516I) in our patients and their families. The p.R644W substitution identified in two unrelated families was the first mutation located in the sterile alpha motif 1 (SAM1) domain. The degree and location of the lentigines were variable across individuals, even if they shared the same SASH1 mutation. All mutations were predicted to be deleterious by six different algorithms used to evaluate the functional impact of a variation. In addition, immunohistopathological findings and RNA sequencing results suggested that SASH1 mutations were associated with an increase in the number of melanocytes, acceleration of melanogenesis, and upregulated hair keratin expression.

The Effect of a Frequency-Doubled Q-Switched Nd:YAG Laser on Hairless Mice Harboring Eumelanin and Pheomelanin in the Epidermis.

BACKGROUND: For laser therapy, darker skin types should be carefully treated, however, the precise role of melanin content, subspecies, and the heat effect of the laser has not been well studied in vivo. METHODS: We generated three groups of mice that have epidermal melanocytes producing only eumelanin, dominant pheomelanin, and no melanin. Using these mice, the effect of a frequency-doubled Nd:YAG laser was studied. RESULTS: The mouse epidermis that contained eumelanin underwent heat degeneration at a lower fluence when compared with the mouse epidermis with dominant pheomelanin. The mouse skin with no melanin did not show any degeneration of the epidermis. CONCLUSION: The effect of the Nd:YAG laser on the cells containing different melanin subspecies was shown to be different in an in vivo irradiation system.

Intralymphatic histiocytosis in a patient with lung adenocarcinoma treated with pembrolizumab: a case report.

BACKGROUND: Pembrolizumab, an anti-programmed cell death-1 protein monoclonal antibody, is effective for patients with advanced non-small-cell lung cancer. However, immune checkpoint inhibitors such as pembrolizumab induce various immune-related adverse events, involving the lung, liver, gastrointestinal, endocrine system, and skin. Intralymphatic histiocytosis (ILH) is a rare, chronic cutaneous disorder with a reactive inflammatory component, which often occurs in patients with rheumatoid arthritis. CASE PRESENTATION: We present a 67-year-old man with lung adenocarcinoma who developed ILH associated with pembrolizumab treatment. He was treated with palliative thoracic radiotherapy for superior vena cava syndrome. Subsequently, he received four cycles of pembrolizumab. Approximately 2.5 months after the initiation of pembrolizumab, he developed erythema on the trunk of his body. Based on findings of skin biopsies, he was diagnosed with pembrolizumab-induced ILH. Moreover, the upregulation of tumor necrosis factor-α was observed during pembrolizumab therapy. CONCLUSIONS: This is the first report of ILH induced by pembrolizumab in a patient with lung adenocarcinoma.

Two Cases of Verrucous Carcinoma: Revisiting the Definition.

Verrucous carcinoma (VC) is an uncommon, distinct type of well-differentiated squamous cell carcinoma. Here we present two cases of VC, one arising from the lower leg and the other from genital skin. Case 1, a female patient, aged 95 years, had a brownish verrucous plaque on her right lower leg. Histopathologically, epithelial tumor cells grew pushing the stroma, while the basement membrane was intact. No prominent cellular atypia or hyperchromatin was found. Case 2, a male patient, aged 53 years, had a verrucous plaque at the border between his scrotum and inner aspect of his thigh. A pathological diagnosis of VC was made using an excisional specimen. Making a definitive diagnosis of VC is challenging but crucial. Pathological diagnosis using a small specimen might cause underdiagnosis or overdiagnosis. To avoid this, pertinent pathological diagnosis using an ample specimen is required. We also revisited the definition of VC to precisely understand its nature.

Assessment of medication adherence and treatment satisfaction in Japanese patients with psoriasis of various severities.

Psoriasis is a chronic, relapsing, inflammatory keratotic skin disease. To elucidate the medication adherence and treatment satisfaction, we performed a questionnaire survey using the eight-item Morisky Medication Adherence Scale (MMAS-8) and nine-item Treatment Satisfaction Questionnaire for Medication (TSQM-9) of 163 psoriatic patients who regularly visited hospitals or clinics. To assess the relationship between the MMAS-8/TSQM-9 outcomes and severity of psoriasis, two different clinical severity indices were used: the Psoriasis Area and the Severity Index (PASI) for disease severity and the Psoriasis Disability Index (PDI) for quality of life (QOL) impairment. The MMAS-8 score for oral medication was significantly higher than that for topical medication. The oral and topical MMAS-8 scores were significantly correlated with the PDI score, but not with the PASI score, indicating that QOL impairment lowered treatment motivation. All of the TSQM-9 domain scores (effectiveness, convenience and global satisfaction) were significantly correlated with both the PASI and PDI scores, suggesting that patients whose skin and QOL conditions were under good control had high satisfaction with treatment. Patients treated with biologics had higher satisfaction than those treated with non-biologics.

A Case of a Giant Cell Tumor of the Tendon Sheath of the Middle Phalanx of the Fourth Toe.

Giant cell tumors of the tendon sheath (GCT-TS) are one of the most common tumors of the hand, along with ganglions. However, occurrence in the toes is far less common. Here we present a rare case of GCT-TS at the middle phalanx level of the flexor digitorum longus tendon sheath. Magnetic resonance imaging showed low intensity both on T1 and T2 weighted images. To the best of our knowledge, our case is the first report of a GCT-TS arising at the middle phalanx level of the flexor digitorum longus tendon sheath of the fourth toe. Although GCT-TS are rare in the toe, they must be included in the differential diagnoses of soft tissue tumors arising in the toes.

A Case of External Dental Fistula Related to a Fixed Cantilever Bridge.

An external dental fistula is a skin manifestation caused by an underlying dental problem. We report a rare case of external dental fistula associated with a fixed cantilever denture. A 77-year-old Japanese woman presented with an enlarging reddish granulomatous lesion on her right cheek that was diagnosed as an external dental fistula. A fixed cantilever denture had initially been attached to her upper jaw with her seven bona fide teeth. However, six teeth were completely lost and the denture was attached to only one tooth, which showed apical periodontitis. Subsequently, the external dental fistula developed. We should keep in mind that a patient with a fixed cantilever denture can suffer from apical periodontitis and a subsequent external dental fistula due to a failure to maintain appropriate oral hygiene.