Home Phototherapy 2

 Home Phototherapy 2

Sunscreens with excessively high SPF values may induce contact dermatitis and cause unnecessary waste.

51. How to Correctly Use Sunscreen After Home Phototherapy?

Answer: Try to avoid sun exposure on the day of home phototherapy. If going out is necessary, use sunscreen correctly as follows: 1. Apply 15 - 30 minutes before going out. 2. Use a sufficient amount, reaching 2mg/cm². The Expert Consensus on Skin Sunscreen (2017) recommends applying an amount the size of a 1-cent coin to the entire face [8]. 3. Reapply sunscreen about 30 minutes after sun exposure. 4. Reapply at least every 2 - 3 hours. 5. Reapply immediately after sweating, swimming, or friction, as these will reduce the thickness of the sunscreen. For enhanced skin recovery, some patients incorporate red light therapy for home alongside uv light therapy routines.

52. Is It Necessary to Use a Moisturizer After Phototherapy?

Answer: Yes. Phototherapy can cause adverse reactions such as dry skin and itching. It is recommended to use a moisturizer after phototherapy to relieve these symptoms. For patients with psoriasis, moisturizing is a basic nursing measure. Use a moisturizer at least twice a day, especially after whole-body phototherapy. Complementing this with phototherapy light sessions can further soothe irritation.

53. After Receiving Home Phototherapy, Can I Skip Hospital Follow-ups?

Answer: No. Patients undergoing home phototherapy should have regular hospital follow-ups, generally once every 1 - 3 months. Doctors will adjust the phototherapy dose or treatment plan based on the phototherapy effect. The specific frequency of follow-ups depends on the condition and doctor's advice. In addition, if there are changes in the medications used, consult a doctor promptly.

Vitiligo and Psoriasis Home Phototherapy 300 Questions

There is no difference in therapeutic effect between full-body and half-body phototherapy devices. The difference is: for generalized skin lesions, a full-body device can complete the treatment at one time, while a half-body device can only irradiate the front/back side of the body at a time. Treating the whole body requires two irradiations, and each treatment takes twice as long as with a full-body device. Red light therapy for home may serve as a supplementary option for inflammation reduction in such setups.

29. What to Note When Purchasing a Home Phototherapy Device?

Answer: First, pay attention to purchasing a home phototherapy device that has market approval and is available for patients to use at home. When purchasing, choose a home phototherapy device approved by the NMPA with a Medical Device Registration Certificate of the People's Republic of China, and the intended user in the registration certificate should clearly state that it is for patients' self-use. Patients can query detailed product information, including the manufacturer and model, on the NMPA official website using the registration certificate number indicated in the manual. Note that its scope of application is for patients' self-use (Figure 2-6) rather than for medical institutions only (Figure 2-7).

Compared with devices used in medical institutions, self-use devices involve not only the guarantee of effectiveness but also the safety of use. Home and medical devices differ in requirements for the use environment and device performance parameters. Carefully read the manual, check the instructions on the use environment in the manual, and verify whether it is suitable for home use. Do not mistakenly purchase medical devices to avoid increasing use risks.

Figure 2-6: Screenshot from the official website of the National Medical Products Administration. The product model in the figure can be "used by patients for self-treatment".

Figure 2-7: Screenshot from the official website of the National Medical Products Administration. The product model in the figure is "for medical institutions" use.

Second, pay attention to selecting a phototherapy device with the correct treatment wavelength under the guidance of a doctor. Be careful not to mistakenly choose a disinfection product with UVC as the main wavelength.

There are many phototherapy devices on the market (especially online), including some counterfeit and inferior products. Such products may not achieve therapeutic effects and even have certain safety hazards. Be sure to identify them when purchasing. Consider integrating face light therapy options for targeted facial treatments.

30. Can the 308nm Wavelength Be Used for Home Phototherapy?

Answer: There are three light sources for 308nm phototherapy: 308 excimer laser, 308 excimer light, and 308 LED light. The characteristics of 308nm ultraviolet phototherapy devices with these three light sources are detailed in Table 2-3. Compared with phototherapy devices with fluorescent tubes as light sources, all types of 308nm light sources have significantly higher output power, shorter time to reach the effective cumulative dose, and faster onset of effect. At the same time, because the irradiation spot of 308nm phototherapy devices is small and only irradiates the lesioned area (also called targeted phototherapy), it is more suitable for the treatment of small-area skin lesions.

When selecting home phototherapy devices, in addition to considering effectiveness, the safety of device use and whether unnecessary adverse reactions will occur are also extremely important measurement standards. Based on this, the National Medical Products Administration has approved 308nm LED small phototherapy devices for patients to self-treat under the guidance of a doctor.

Table 2-3: Characteristics of 308nm Ultraviolet Phototherapy Devices with Three Different Light Sources

31. How to Reasonably Select an Appropriate Home Phototherapy Device?

Answer: Select a phototherapy device based on the size and location of your skin lesions. For large-area or generalized skin lesions, it is recommended to use a full-body or half-body phototherapy device, which can save single treatment time. For small-area skin lesions, a handheld phototherapy device can be selected to reduce ultraviolet exposure to surrounding normal skin. For specific locations, phototherapy devices or accessories specially designed for that location can be selected. For example, a phototherapy comb with good light-guiding properties can be selected for scalp lesions (Figure 2-8). Red light therapy for home can be a gentle alternative for scalp soothing post-uv light therapy.

Figure 2-8: Handheld Phototherapy Device Equipped with a Phototherapy Comb.

32. What Is a Home Phototherapy Device with a Built-in Automatic Timer?

Answer: A phototherapy device with a built-in automatic timer is relatively intelligent. It can automatically count down after the treatment starts (Figure 2-9) and automatically stop irradiation when the set dose or time is reached, which can better avoid over-irradiation. For phototherapy devices without a built-in automatic timer, manual timing is required, and the phototherapy device is turned off manually after the treatment time is reached.

Figure 2-9: Phototherapy Device with Automatic Countdown Function.

33. How to Set the Irradiation Dose and Treatment Time During Home Phototherapy?

Answer: The main parameters of NB-UVB home phototherapy devices include irradiation time (s), irradiation dose (mJ/cm²), and irradiation intensity (mW/cm²). The conversion formula among them is: Irradiation time (s) = Irradiation dose (mJ/cm²) / Irradiation intensity (mW/cm²).

Some phototherapy devices can directly set the irradiation dose. After entering the required irradiation dose, press the start button to begin treatment. Some phototherapy devices require entering the irradiation time. In this case, the required irradiation time for the current treatment needs to be calculated according to the formula based on the required irradiation dose for the current treatment before setting. The irradiation intensity of home phototherapy devices is usually clearly marked on the device. Based on the irradiation intensity of the device used, patients calculate the required irradiation time according to the formula, and then enter the time for the current treatment into the phototherapy device controller to start the treatment. Phototherapy light settings ensure precise dosing.

34. What Is the Maximum Single Irradiation Time of a Home Phototherapy Device?

Answer: The maximum single irradiation time varies for different phototherapy devices. According to the provisions of the Chinese pharmaceutical industry standard YY 0901-2013, the maximum set dose of UVB phototherapy devices is 5J. The intensity of different models of home phototherapy devices varies, and the maximum single irradiation time of the phototherapy device you use can be calculated according to the formula.

35. After Receiving Phototherapy in the Hospital for a Period of Time, How to Adjust the Treatment Dose When Switching to Home Phototherapy?

Answer: Phototherapy devices in hospitals and homes are different, and the irradiation intensity varies, so the irradiation time will also differ for the same dose. If a patient switches from hospital phototherapy to home phototherapy, first understand the current irradiation dose, then reduce the current dose by 20% as the initial irradiation dose for home phototherapy, or consult an experienced doctor to formulate the initial home treatment dose.

36. Can the Tube of a Home Phototherapy Device Be Used Continuously?

Answer: No. Fluorescent tubes have a certain lifespan. During use, the irradiation intensity of the tube will gradually decrease as the usage time increases. It is usually recommended to replace the fluorescent tube when it has been used for about 500 hours; otherwise, the therapeutic effect will be affected. Generally, the manual will recommend the tube replacement time. You can contact the manufacturer regularly for intensity measurement and tube replacement. It should be noted that after replacing the tube, the treatment dose should be reduced to 80% of the previous dose to prevent burns due to the large difference in irradiation intensity between the new and old tubes.

Clinically, many patients consult why home phototherapy was effective last year but not this year after a recurrence. This is likely related to the decreased irradiation intensity of the phototherapy device tube. Patients can estimate the tube usage time based on their total phototherapy dose.

If it is a home phototherapy device with an LED light source, its irradiation intensity decreases very slowly and can be used for thousands of hours.

37. Is It Necessary to Read the Instructions of the Treatment Device Before Home Phototherapy?

Answer: It is very necessary. Patients must carefully read the accompanying instructions before operating the home phototherapy device by themselves and use it according to the instructions to ensure the best therapeutic effect, reduce adverse reactions, and correctly use the phototherapy device to extend its service life.

38. Is It Necessary to Formulate a Phototherapy Plan with a Doctor Before Home Phototherapy?

Answer: Yes. Home phototherapy is a method in which patients operate the home phototherapy device by themselves under the guidance of a doctor. Patients should follow the phototherapy plan formulated by the doctor. The doctor will formulate the phototherapy plan based on the patient's current treatment medications and other comprehensive considerations. In addition, patients should have regular hospital follow-ups during home phototherapy to ensure the correctness and effectiveness of the treatment.

39. Is It Necessary to Pay Attention to Diet During Home Phototherapy?

Answer: Yes. During phototherapy, ingesting a large amount of photosensitive foods may cause phototoxic reactions in the phototherapy area. Therefore, during phototherapy, try to reduce the intake of photosensitive foods. Common photosensitive foods include Chenopodium album, Ziyun vegetable, fig, mud snail, amaranth, shepherd's purse, radish, rape, mustard, beet, Indian lettuce, spinach, Salsola collina, purslane, chicory, buckwheat, pagoda tree flower, fungus, grapefruit, celery, etc. Avoid eating large amounts of the above foods during phototherapy.

40. Do Medications for Underlying Diseases Such as Hypertension and Diabetes Affect Home Phototherapy?

Answer: They may affect. Many commonly used drugs for these underlying diseases are photosensitive, such as the diuretic hydrochlorothiazide, the hypoglycemic drug glipizide, and cardiovascular drugs such as captopril and nifedipine. Therefore, patients undergoing phototherapy must inform their doctor of the medications they are currently taking so that the doctor can formulate a suitable phototherapy plan. If there are adjustments to medications for other diseases, communicate with the doctor promptly to adjust the phototherapy plan accordingly.

41. Is It Necessary to Cover the Eyes During Phototherapy?

Answer: Yes. During phototherapy, the operator needs to wear goggles, and patients also need to wear goggles or cover their eyes. Ultraviolet rays can damage the eyes, so eye protection must be done. If treating skin lesions around the eyes, be sure to keep the eyes tightly closed and do not look directly at the light-emitting part or tube of the phototherapy device. If the patient is a child, the treatment must be carried out with the assistance and accompaniment of a guardian to ensure that their eyes remain tightly closed during treatment. Face light therapy around the eyes requires extra caution.

42. Is It Necessary for Men to Cover Their Genitals During Phototherapy?

Answer: Yes. Without protection, the male genital area may increase the risk of tumor development after repeated phototherapy over a long period, so phototherapy is not recommended. Literature reports that 14 male psoriasis patients developed malignant tumors in the genital area after PUVA treatment [7]. Although PUVA has been basically replaced by NB-UVB, for safety reasons, phototherapy is still not recommended for the male genital area. There is no phototherapy contraindication for the female vulva.

43. Is It Necessary for Women to Cover Their Areolas During Phototherapy?

Answer: Yes. During phototherapy, the areola area needs to be covered or have sunscreen applied to prevent burns.

44. How to Reduce Sun Exposure After Phototherapy?

Answer: After phototherapy, reduce sun exposure or exposure to artificial light sources, especially in the phototherapy area. On the day after ultraviolet treatment, the treatment area should avoid additional sunlight exposure. Try not to go out. If going out is necessary, avoid going out during the noon when the ultraviolet index is the highest, shorten the time spent outdoors; wear clothes with protective functions, wide-brimmed hats, and sunglasses; use a broad-spectrum sunscreen with a sun protection factor (SPF) > 15; when taking transportation, avoid the side exposed to sunlight; and try to avoid contact with artificial light sources.

45. What Is the Physical Light-blocking Method?

Answer: The physical light-blocking method uses various items that prevent ultraviolet radiation to minimize ultraviolet damage to the human body, including clothing, hats, sunglasses, umbrellas, etc.

46. What Kind of Clothing Should Be Chosen for Sun Protection?

Answer: Choose clothing with an anti-ultraviolet coating on the surface or made of anti-ultraviolet fiber textile fabric. The anti-ultraviolet ability of clothing is expressed by the ultraviolet protection factor (UPF). The larger the UPF value, the better the protection ability. The Chinese standard is: UPF > 30 and UVA transmittance < 5% to be called an anti-ultraviolet product, marked as UPF30. The best protective product is UPF > 50, marked as UPF50.

47. What Types of Sunscreens Are There?

Answer: According to different ingredients, sunscreens can be divided into physical sunscreens and chemical sunscreens. The active ingredients in chemical sunscreens can selectively absorb ultraviolet rays to achieve sun protection. The active ingredients in physical sunscreens are often opaque substances that cannot absorb ultraviolet rays but can reflect or scatter them. In recent years, the combined use of chemical and physical sunscreen ingredients has become very common.

In addition, there are broad-spectrum sunscreens and water-resistant sunscreens. When the critical wavelength of the product's sunscreen spectrum is ≥ 370nm, the product can be labeled as having broad-spectrum sunscreen effect. The water resistance test method for sunscreen is to apply the sunscreen to human skin and then determine its SPF value after a 40min or 80min repeated cyclic water immersion (water resistance test). Water-resistant sunscreens should be used in situations such as outdoor sports sweating, underwater operations, or sea water baths.

48. What Does SPF on Sunscreen Mean?

Answer: Sunscreens are labeled with SPF15, SPF30, etc. SPF is the abbreviation of Sun Protection Factor, which evaluates the ability of sun protection cosmetics to prevent sunburn. The larger the SPF value, the better the protection effect. SPF is defined as the ratio of the UVB irradiation dose required to produce the minimum erythema on the skin area where the sunscreen is used to the irradiation dose required on normal skin. The larger the minimum erythema dose after using sunscreen, the larger the ratio, and the better the sun protection effect. Therefore, a larger SPF value indicates a better sun protection effect.

49. What Does PA on Sunscreen Mean?

Answer: PA represents the UVA protection grade (Protection of UVA, PA) of sun protection products, identified based on the UVA protection factor (Protection Factor of UVA, PFA) of the sun protection product. PFA is the ratio of the minimum persistent pigment darkening dose (MPPD) required for the skin protected by the sun protection product to that of unprotected skin. The corresponding relationship between PFA and PA is: PFA < 2 indicates no UVA protection effect; PFA 2 - 3 is marked as PA+; PFA 4 - 7 is PA++; PFA ≥ 8 is PA+++.

50. How to Choose Sunscreen After Home Phototherapy?

Answer: There is no need to blindly pursue a high sun protection factor when choosing sunscreen. It should be selected based on the daily exposure time. For those who mainly work indoors, a sunscreen with SPF around 10 and PA+ can be selected; for outdoor workers, a sunscreen with SPF around 20 and PA++ is suitable. It is not recommended for phototherapy patients to be exposed to the sun for a long time. If a patient may be active in strong sunlight or have sea water baths, a water-resistant sunscreen with SPF ≥ 30 and PA+++ should be selected. It should be noted that a higher SPF value is not necessarily better. Excessive use of high-SPF sunscreens...