Impaired Skin Barrier Due to Sebaceous Gland Atrophy in the Latent Stage of Radiation-Induced Skin Injury: Application of Non-Invasive Diagnostic Methods

Clinical Effect of Moisturized Skin Care on Radiation Dermatitis of Head and Neck Cancer

BACKGROUND/AIM

Radiation therapy (RT) for head and neck cancer may cause severe radiation dermatitis (RD) resulting in RT interruption and affecting disease control. A few studies address skin moisture changes during RT for head and neck cancer. The purpose of this study was to explore the effect of moisturized skin care (MSC) on severity of RD.

PATIENTS AND METHODS

The study includes newly diagnosed head and neck cancer patients undergoing RT. Participants were divided into MSC group and routine skin care (RSC) group based on patient's preferred decision. Skin moisture in the four quadrants of the neck was measured weekly before and after RT. RD was assessed with the Radiation Induced Skin Reaction Assessment Scale (RISRAS) and the Radiation Therapy Oncology Group (RTOG) acute skin toxicity grading criteria.

RESULTS

A total of 54 patients were enrolled, of which 49 patients were suitable for the statistical analysis. There was a statistically significant difference in the RISRAS total score since the 5th week after RT between the groups. The severity of RD was less (B=0.814, p=0.021) and the onset was later (B=-0.384, p=0.006) in the MSC group when compared to the RSC group. Skin moisture decreased with cumulative radiation dose. In the upper neck, the MSC group had a slower rate of skin moisture decrease compared to the RSC group (right upper neck: B=0.935, p=0.007; left upper neck: B=0.93, p=0.018).

CONCLUSION

MSC can effectively reduce the severity and delay the onset of RD, while slows down skin moisture decrease during RT.

Effect of standard skin care treatments on skin barrier function in X-irradiated hairless mice

Objective

The effectiveness of skin care to radiation dermatitis (RD) on patients who received radiotherapy for cancer has not been clarified. The purpose of this study was to investigate the effect of moisturizers and skin washing on skin barrier function possibly leading to the development of RD using X-ray irradiated hairless mice.

Methods

Nine-week-old hairless mice were irradiated with 10 ​Gy of X-rays, and the skin care group had moisturizers applied or skin washing with soap from the day of irradiation during observations. The condition of the skin was observed to evaluate RD. Skin barrier function was evaluated by measuring skin temperature and transepidermal water loss (TEWL) once every two days until 25 days after X-ray irradiation.

Results

RD was not observed in all groups until 25 days after X-ray irradiation. Skin temperature tended to increase in all groups regardless of irradiation or skin care. However, unlike the control group, the measured value of TEWL in the no skin care group tended to increase in the days after the X-ray irradiation. On the other hand, TEWL was increased in the skin care group compared with the no skin care group a few days after X-ray irradiation. While TEWL was constant in the moisturizer group, the skin washing groups showed an increasing tendency of TEWL and it reached a peak at 13 days after X-ray irradiation.

Conclusions

These results suggested that the decrease in skin barrier function was caused by X-ray irradiation and also that skin washing could contribute to the deterioration of skin barrier function after X-ray irradiation.

Objective Skin Quality Assessment after Reconstructive Procedures for Facial Skin Defects

Local random skin flaps and skin grafts are everyday surgical techniques used to reconstruct skin defects. Although their clinical advantages and disadvantages are well known, there are still uncertainties with respect to their long-term results. Hence, the aim of this study was to evaluate outcomes more than one-year post operatively using objective measurement devices. The study included 31 facial defects reconstructed with local random flap, 30 facial defects reconstructed with split-thickness skin grafts (STSGs) and 30 facial defects reconstructed with full-thickness skin grafts (FTSGs). Skin quality was objectively evaluated using MP6 noninvasive probes (Courage + Khazaka GmbH, Cologne, Germany), which measure melanin count, erythema, hydration, sebum, friction and transepidermal water loss. The results showed that there were no significant differences in melanin count, erythema, hydration, sebum level, friction value and transepidermal water loss (TEWL) between the site reconstructed with random local flaps and the same site on the healthy contralateral side of the face. However, both FTSGs and STSGs showed significantly higher levels in terms of TEWL and erythema, whereas the levels of hydration, sebum and friction were significantly lower compared to the healthy contralateral side. Moreover, STSGs resulted in a significant difference in melanin count. These findings imply that the complex pathophysiology of the wound-healing process possibly results in better skin-quality outcomes for random local flaps than skin autografts. Consequently, this suggests that random local flaps should be implemented whenever possible for the reconstruction of facial region defects.

Comparison of structural components and functional mechanisms within the skin vs. the conjunctival surface

PURPOSE OF REVIEW

The purpose of this review is to highlight and compare the structural and functional differences between the ocular surface and the skin. The goal is to further understand how these components interact from an immunobiological standpoint, which may inform future therapeutic uses.

RECENT FINDINGS

Treatment agents, such as Dupilumab and Apremilast are traditionally indicated for integumentary conditions, such as atopic dermatitis and psoriasis, respectively. Both were also found to have potent effects on the conjunctival surface and ocular glands, which may be attributed to the similarities in structure.

SUMMARY

Surfaces of the eyes and the skin are found to have similar composition in terms of immunohistology, steroidogenic properties, and allergic mechanisms. These translate directly into both the adverse effects and therapeutic benefits that overlap when treating these surfaces.

Effects of Delgocitinib Ointment 0.5% on the Normal Mouse Skin and Epidermal Tight Junction Proteins in Comparison With Topical Corticosteroids

Delgocitinib ointment 0.5% is the world's first topical Janus kinase inhibitor product and was approved for treatment of atopic dermatitis (AD) in Japan. Although topical corticosteroids (TCSs) have been the mainstay of pharmacotherapy in AD over the past decades, long-term use of TCSs causes skin atrophy and alteration of the epidermal tight junction (TJ) leading to epidermal barrier dysfunction. In this study, delgocitinib ointment 0.5% or representative TCSs of different potencies were applied dermally once daily to the ear pinna of normal ICR mice for 14 days, and ear pinna thickness, histopathology, and immunohistochemistry for epidermal TJ proteins claudin-1 and -4 were evaluated. All the TCSs caused decreases in ear pinna thickness with epidermal thinning, sebaceous gland atrophy, and atrophy/decreased number of the subcutaneous adipocytes and decreased immunohistochemical staining intensity for epidermal claudins. In contrast, delgocitinib ointment 0.5% did not cause any of those changes. In conclusion, once daily topical delgocitinib ointment 0.5% for 14 days did not cause skin atrophy or decreased immunohistochemical staining of epidermal claudins, which are common safety concerns associated with TCSs. These characteristics suggest that delgocitinib ointment 0.5% has an improved safety profile over currently available TCS therapies particular for the long-term AD treatment.