Presentation on theme: "Frederick C. Fehl, III MD Dept of Dermatology SCPMG San Diego"— Presentation transcript:
1 Frederick C. Fehl, III MD Dept of Dermatology SCPMG San Diego PHOTOTHERAPY UPDATE 2009Frederick C. Fehl, III MDDept of DermatologySCPMG San Diego
2 DisclosuresI have no known conflicts with any of the products, medications or devices, discussed in this lectureI am receiving no honoraria
3 The Electromagnetic spectrum Figure shows electromagnetic spectrum divided into the major regions:UVA (UVA I and UVA II )UVBUVC
4 UV SpectrumUVC ( nm)An arbitrary division was made between UVB and UVC at 290nm because wavelengths shorter then 290nm do not reach the earth’s surfaceAbsorbed by the ozone layerThese wavelengths are absorbed by DNA, RNA and proteins of cells and can be lethal to organismsHence the term germicidal radiationUsed in germicidal lamps that emit 254nm
5 UV Spectrum UVB (280-320nm) Strongly erythemogenic (sunburn rays) Ordinary window glass filters out wavelengths shorter then 320nmThere is great variation of the erythemogenic potential within the range:For example 297nm is nearly 100 times more erythemogenic then 313nm radiation even though they are both in the UVB spectrum
6 UV SpectrumUVA ( nm)Divided into two groups:UVA1 ( nm) andUVA2 ( nm)aka as “tanning rays” (tanning parlors emit)Not blocked by window glass unless…UVA radiation is more deeply penetrating (penetrates to the deeper dermis whereas UVB is absorbed by the epidermisThis is why I often refer to it as the wrinkle rays
7 UV FACTS Ultraviolet light is “light” we can not see…it’s radiation! Comprises 5% of terrestrial radiationIt spans the region of “light” from 400 to 100nmUV is 7% more intense in the Southern Hemisphere summer than Northern Hemisphere summerUVB comprises 5% of total UV compared to 95% for UVA…but UVB is more biologically active!
8 UV FACTS On a cloudy day…66% of UV gets to ground (75% in the tropics) In the tropics….a cloudy day get 75% to groundReflection off the ground is less than 10% except for snow which can reflect 90%!Choppy water more reflective than calm waterFor every 1,000 feet in elevation, there can be 7% more UVWhat about the Ozone depletion?
9 “Their may be more ozone depletion in Blue States then Red States” Red States vs. Blue States Summary 2008 Election Results “Their may be more ozone depletion in Blue States then Red States”Bush, Limbaugh et al
10 UV FACTS UVB inflammation is a delayed effect: Develops 1-5 hrs after high doseMax effect at 24 hrsfades in 3 daysUVA inflammation is immediate (immediate pigment darkening)The UVA “tan” offers little protection compared to UVBUVA penetrates deep to dermis…UVB affects epidermis
11 UV FACTS UVB is considered more carcinogenic: AK, SCC and BCC’s UVA does have detrimental clinical effects ( e.g., flares autoimmune skin diseases such as lupus etc, has been linked to melanoma)UV can be our friend…Vitamin D, mood elevationUV is immunosuppressive!70% of UV damage occurs before age 20!
13 Historical Aspects: Phototherapy Ancient times: Topical exposure to plants containing psoralens + natural sunlight used in Egypt and India to treat vitiligo1925: Use of crude coal tar and UV radiation was introduced by Goeckerman (Mayo Clinic); became the standard therapy for psoriasis for the next 50 years1974: PUVA developed (oral regimen)PUVA was quite effective for severe psoriasis1970’s: broadband UVB also introducedBB UVB IF given in doses that produce a slight erythema could clear mild psoriasis
14 Mechanisms of Action of UVL Reduction in skin proliferation (1st way):UVL is absorbed by chromophoreThe most important chromophore for UVB is DNAPyrimidine dimers are formedThese toxic photoproducts reduce DNA synthesisReduction in skin proliferation (2nd way):UVL induces the expression of p53 tumor suppressor genep53 causes cell cycle arrest and/or apoptosis (cell death)
15 Mechanisms of Action of UVL Immunosuppressive effects:Induces Interleukin 6 and 10 (sunburn sxs)Langerhans cells (antigen presenting cells) are inhibited by UVLKeratinocytes release IL-1 and 6, Prostaglandins E2 and TNF-αSecretion of these compounds alters the local immune response and may contribute to suppression of disease
16 Action SpectrumThe effectiveness of clearing psoriasis plotted against wavelength is defined as the action spectrum of phototherapyIt is most desirable to use wavelengths (λ) which are maximally therapeutic and minimally erythemogenic
17 Action SpectrumStudies in the early 1980’s demonstrated that 304 and 313nm had the optimal anti-psoriatic effect within the UVL spectrum:For wavelengths shorter then 295nm, no improvement in psoriasis occurred (remember shorter λ’s are more erythemogenic then therapeutic)304nm313nm<295nmParrish, JA and Jaenicke, KF J Invest Dermatol 1981; 76:
18 Action SpectrumThe Philips Corp armed with the knowledge regarding the action spectrum of psoriasis develops a fluorescent lamp, TL 01, that emits the optimal narrow band UVB frequency: nm
19 Differences: broadband and narrowband UVB NB UVB is much less erythemogenic then BB UVBFor example: 297nm is nearly 100 times more erythemogenic then 313nm radiation even though they are both in the UVB spectrumShown to be as effective as PUVA in the treatment of psoriasisTheoretically safer then BB UVB or PUVA
24 Pre-treatment Check List: UV Therapy Review the patient’s history (Snapshot)?What disease is the MD treating?Does the patient have co-morbidities that may make UV contraindicated?
25 Diseases Treated with UV Psoriasis, psoriasis, and mostly psoriasisAtopic DermatitisPMLEPruritus of renal failurePruritus of liver Disease (e.g., PBC)SclerodermaIdiopathic Pruritus of unknown etiologyCTCLVitiligoEosinophilic folliculitis of HIVWinter Mood Affective Disorder
26 Pre-treatment Check List: UV Therapy Review the patient’s history (Snapshot)?What disease is the MD treating?Does the patient have co-morbidities that may make UV contraindicated?
27 UV AGRAVATED DISEASES PMLE SLE DLE SCLE Solar Urticaria Xeroderma PigmentosaChronic Actinic DermatitisCockayne’s Syndrome, BloomsPCTDermatomyositisPemphigusActinic ReticuloidActinic LP
28 Pre-treatment Check List: UV Therapy Review the Medications List:Are there any medications listed that are photosensitizing?Will they be using any topical medications in conjunction with their UV therapy?DovonexVecticalTazoracAre they taking any oral agents to facilitate their Rx?Acitretin, Isotretinoin
29 Medications known to cause photosensitivity Every light box facility should have a list such as this one to cross check medications prior to starting UVBExamples include:Zanolli et al textbook: Phototherapy Treatment Protocols (listed in KP protocol)Litt’s Drug Eruption Reference Manual will also list
30 Pre-treatment Check List: UV Therapy Labs:Did the MD order any pre-treatment labs?Physical Exam:Do you agree with the MD’s Fitzpatrick skin type assessment?Orders:Do the orders make sense!Right protocol for the diseasec/w published protocolsBroadband UVB vs. Narrow Band UVB
31 How do you do it? What mj do you start at? How much do you increase at each visit?What happens if you miss a day, a week or a month?What happens if the patient sunburns?Do you ask if the patient started any new meds?
32 Dosing determination for UVB Optimal done uses minimal erythema dose determination (MED) for individual patients by intricate phototestingNot typical used by most Dermatologists since it is time consuming and nurse intensiveMost Dermatologists use schedules based on the patients skin type
35 Response to Sun Exposure Fitzpatrick Skin TypeFitzpatrick Skin TypeResponse to Sun ExposureExamplesIAlways burns, never tansFair skin and freckles, blue eyed, CeltsIIAlways sunburns, tans minimallyFair skin, blond hair, blue eyes, ScandinavianIIISometimes sunburns, tans moderatelyFair skin, brown hair, brown eyes, unexposed skin is whiteIVSeldom sunburns, tans easilyLight brown skin, dark hair, brown eyes, unexposed skin is tan; Mediterranean, HispanicVRarely sunburn, tans profuselyBrown skin; Darker Mediterranean, some Asians, Pacific Islander, Indian subcontinentVINever sunburns, deeply pigmentedAfrican Americans
42 Initial NB UVB Dosing based on Fitzpatrick Skin Type Tanning ResponseInitial NB UVB DoseIAlways burns, never tans100 mJIIUsually burn, tans with difficulty220 mJIIISometimes mild burn, tan average260 mJIVRarely burns, tans with ease330 mJVVery rarely burns, tans very easily350 mJVINo burn, tans very easily400 mJKaiser Protocol dated 10/15/07
43 UVB Phototherapy for Psoriasis Ideally 3X a week (Dr. Koo recommends up to 5X a week)Combination therapy is ideal!Calicipotriene + UVB 2X/week = UVB 3X/weekTazarotene 3X/week added to UVB requires less than ¼ of UVB to achieve 50% PASIGoeckerman, Anthralin, Keratolytics
44 Current Kaiser Recommendations regarding Dose Escalation based on Skin Type for NB UVB Interval IncreaseEstimated Dose GoalMaximum Dose(not to exceed)I15mJ520 mJ2000mJII25mJ880 mJIII40mJ1040 mJ3000mJIV45mJ1320 mJV60mJ1400 mJ5000mJVI65mJ1600 mJ
45 Key Safety Points …….Burn Unit!!! Type of box: Remember units matter: NB vs. BBFor clinics with multiple boxeseven if same light systemwe assign a pt to a particular boxthey always use that box even if they have to wait!Remember units matter:800 milljoules vs. 800 Joules…….Burn Unit!!!
46 Two different boxes with two different input metrics
54 NB UVB Protocols Remember different diseases use different protocols Vitiligo protocol quite different then psoriasisAtopic dermatitis protocol different then psoriasis (e.g., much lower max dose)Remember the Kaiser Permanente protocol is a quite conservative NB UVB protocol for the treatment of psoriasis imho When in doubt whether the protocol is appropriate for the disease being treated ask the ordering MD to verify!
56 Vitiligo NB UVB Protocol Treatment frequency is typically twice weeklyStart at all patients at 200 mJ/ cm2Incremental DosingIf skin was pink the previous night and:Pink now: Skip treatment & notify the MDNot Pink now: Treat at same doseIf skin was not pink the previous night:Increase by 50 mJ/cm2Maximum dose is mJ /cm2Missed Treatments of NBUVB for Vitiligo:4-7 days 100% (same as last dose)8-14 days decrease dose by 50%15-21 days start over
58 What’s New in Phototherapy Narrow Band UVB 311UVA – 1Photodynamic TherapyBlue LightRed LightExcimer LaserNew Lasers
59 UV FACTSUV is a discrete, oscillating electromagnetic pulse of energy, E (joules, J) and a wavelength, lambda (nanometres, nm, 10 -9th m), travelling through space at velocity, c (3x10 8th m/s), such that E=hc/lambda, where h= 6.63 X th J/s (Planck’s Constanat).
60 Common Terms Watt (W) = Unit of power Energy (Joules) = Power (W) x time (sec)Joule (J) = Unit of energy1000 Millijoules (mJ) = 1 JouleFluence (Dose) = Energy delivered to a unit area (J/cm2 )Irradiance = Power delivered to a unit area (W/m2)
Your consent to our cookies if you continue to use this website.