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PHOTOTHERAPY BEYOND PSORIASIS AND VITILIGO
DR. MIKHIN GEORGE THOMAS
• Definition • History• Types of phototherapy
• Mechanism of action• Schedules and protocols• Combination therapy
• Acute and long term effects of
phototherapy• Indications of phototherapy• Newer forms of phototherapy• Extracorpreal photopheresis• Targeted phototherapy
PHOTOTHERAPY• Phototherapy is the use of ultraviolet
radiation or visible light for therapeutic purposes
• UVB radiation (290–320 nm) is absorbed by the epidermis and superficial dermis
• UVA radiation (320–400 nm) can reach the mid- or lower dermis
• Heliotherapy• Atharva veda- Psoralia Corylifolia• 1896-Niels Ryberg Finsen• 1923-Wiliam Henry Goeckerman• 1953- John Ingram
• Revival of phototherapy- Ammi Majus and Bergapten
• PUVA –Fitzpatrick• 1992- UVA1 for atopic dermatitis• 1980s- ECP introduced for CTCL
TYPES OF PHOTOTHERAPY
Ultraviolet A Ultraviolet B Targeted phototherapy
NEWER FORMS OF PHOTOTHERAPY
• Excimer laser• Intense pulse light therapy• Light-based targeted phototherapy• Photodynamic therapy• Balneotherapy
MECHANISM OF ACTION
UV-B Interferes with the synthesis of proteins
and nucleic acids-decreased proliferation of epidermal keratinocytes.
Early changes Formation of pyrimidine dimers Membrane lipid peroxidation Induction of transcriptional factors.
Delayed changes Alteration of antigen presenting cells
and cellular signaling mechanisms- Î IL10,PGE2
Decrease the number of Langerhans cells thus inhibiting the ability of dendritic cells to present antigens.
PUVA Similar to UVB irradiation Penetrates into the dermis Effects on dermal dendritic cells,
fibroblasts, endothelial cells, and mast cells as well as skin infiltrating inflammatory cells including granulocytes and T lymphocytes.
Induces reactive oxygen species formation-cell membrane and mitochondrial membrane damage and eventual death of antigen-presenting cells
Stabilizes the mast cells Upregulates MMP
PSORALENS
Naturally occurring compounds 8-methoxypsoralen (8-MOP)5-methoxypsoralen (5-MOP)4,5′,8-trimethylpsoralen(TMP)
FACTORS
INSOLUBLE IN WATER FOOD HINDERS ABSORPTION FIRST PASS METABOLISM ABSORPTION DEPENDS ON THE PHYSICAL
PROPERTIES LARGE INTERINDIVIDUAL VARIATION IN
ABSORPTION
JAAD 2010
8-Methoxypsoralen, 0.4-0.6 mg/kg, taken 1-2 h before exposure to UVA
UV protective eye wear should be worn when outdoors for 12 h post ingestion
Treatment -2-3/wk Initial improvement frequently seen
within 1 mo of therapy
COMBINATION UVB WITH TOPICAL THERAPIES
Emollients increase the transmission of UV radiation by altering the optical properties of psoriatic skin lesions and
improving therapeutic efficacy Sunscreens
No added benefit with concomitant topical steroid useCalcipotriol use has shown equal efficacy with twice weekly NBUVB when compared to thrice weekly monotherapyWith topical retinoids, better efficacy but NBUVB dosage to be reduced to avoid burning of skin
Combination of methotrexate along with phototherapy reduces the dose related toxicity
Combination with cyclosporine not tried much as monotherapy itself has high chance of non melanoma skin cancers
Other combinations include retinoids and biologics
UV- B
Contraindications: Lupus erythematosus or Xeroderma Pigmentosum Caution should be exercised in: Patients with skin types I and II History of arsenic intake or previous treatment
with ionizing radiation therapy, History of melanoma or multiple nonmelanoma
skin cancers Any medical condition that is severe enough that
patient cannot tolerate heat or prolonged standing in light box
Drug interactions: Cautious use with other photosensitizing medications
When used in conjunction with systemic retinoids, dose of both retinoids and UVB may need to be lowered
Baseline monitoring: Full body skin check before initiation of therapy
Ongoing monitoring: Regular full skin examination to monitor signs of photoaging, pigmentation, and cutaneous malignancies
Pregnancy: Generally considered safe (expert opinion)
Nursing: Generally considered safe (expert opinion)
Pediatric use: No adequate study; may be used with caution in individuals aged\18 y
Psoriatic arthritis: No studies
TOXICITY: PUVA
Acute:
Nausea and vomiting are common Dizziness and headache are rare Erythema: peaks at 48-96 h Pruritus Tanning: starts 1 wk after PUVA Blisters Photo-onycholysis Melanonychia
Chronic: Photocarcinogenesis (SCC, BCC, and
possible melanoma) Increased risk of photocarcinogenesis in
Caucasians with skin types I-III after 200 treatments; this risk not present for non-Caucasians
Photoaging and lentigines are common, especially in patients of skin types I-III and are cumulative UVA dose dependent
Contraindications: Known Lupus Erythematosus, Porphyria, or Xeroderma Pigmentosum
Caution should be exercised: In patients with skin types I and II who tend to burn easily
History of arsenic intake or previous treatment with ionizing radiation therapy
History of melanoma or multiple non melanoma skin cancers
Any medical condition that is severe enough that patient cannot tolerate heat or prolonged standing in light box
Severe liver disease that could lead to toxic levels of psoralens, possibly those who have been treated with cyclosporine or Methotrexate
pregnant or nursing
Caution when patient is taking other photosensitizing medication
Should decrease UVA dose by one-third if oral retinoids are started while patient is receiving PUVA
Skin cancer screening Eye examination ANA panels (anti-Ro/La antibodies) Liver enzymes
Regular full skin examination because of potential increased risk of photocarcinogenesis in Caucasians
In patients who are noncompliant with eye protection, yearly eye examination
Pregnancy: Category C Nursing: Contraindicated for period of 24 h after
ingesting psoralen Pediatric use: No studies; may be used with caution in
individuals aged\18 y Psoriatic arthritis: No studies
FDA APPROVED INDICATIONS
PSORIASIS VITILIGO
OFF LABEL INDICATIONS
Malignancy
• Mycosis fungoides
Inflammatory
• Seborrheic dermatitis
Photodermatoses
• Actinic reticuloid
• PMLE
• Solar urticaria
Clonal disorders
• Parapsoriasis
• Pityriasis lichenoides
Immune dysfunction
• Atopic dermatitis
• Alopecia areata
• Lichen planus
Others
• Granuloma annulare
• Urticaria pigmentosa
• Lichen myxedematous
• Morphoea
MYCOSIS FUNGOIDES (MF): Non-Hodgkin Lymphomas (NHL), which
are characterized by their initial presentation in the skin
MF (together with other types of CTCL) is the only malignant disease that is treated with ultraviolet (UV) radiation, the major environmental skin carcinogen
UVB decreases the allo-activating and antigen presenting capacity of Langerhan cells
Treatment schedule consists of clearance, maintenance and follow up
Histological evaluation of clearing of lesions
Maintenance therapy includes two therapies a week for 1month and then one exposure for a month for 3-6months.
PUVA has been tried in all stages of mycosis fungoides
Most successful in early-stage disease, i.e. less than stage IIa.
Rate of complete remission after an initial course of PUVA- 90% for stage IA, 76% for stage IB, 78% for stage IIA, 59% for stage IIB, and 61% for stage III disease
Once a patient achieves complete remission, a confirmatory biopsy of a previously exposed site is often recommended
Bath PUVA has been utilized as a therapeutic modality in patients in whom oral psoralens cannot be given
There were no differences in time to relapse between patients treated with PUVA and those treated with narrow-band UVB
REASONABLE APPROACH Start with NB-UVB and in case of lack of
response switch to PUVA Patches and thin plaques-NB-UVB In late stage disease-PUVA may be
combined with methotrexate, bexarotene or interferon as first-line therapy
Complete clearing may be induced when the cells are confined to the epidermis and the superficial dermis and do not exceed the depth of UVA penetration into the skin.
PUVA is not sufficient as monotherapy Reduce the tumor burden in the skin Improve the quality of life for patients
ATOPIC DERMATITIS Second‑line treatment in the
management of atopic dermatitis Moderate, severe and
erythrodermic cases respond to PUVA
More difficult to treat Alteration of lymphocyte function
in the dermal infiltrate. Airconditioned treatment cabinets
improve patients tolerance to phototherapy
The action of UVA‑1 is mediated through T lymphocyte apoptosis and decreased expression of interferon γ (IFN‑γ) by activated T cells.
Medium dose UVA1 and NB-UVB phototherapy are most effective as observed in various randomized controlled trials and half‑body paired comparison studies
RELAPSE IS FREQUENT NEED PROLONGED TREATMENT COMBINATION WITH STEROIDS
LICHEN PLANUS
Effective alternative to steroids in disseminated lesions, recalcitrant oral lesions
Response rate – 50 to 90% More sessions Post inflammatory hyperpigmentation More cumulative doses required Re-PUVA a better option
GRAFT VS HOST DISEASE Acute GVHD shows good response Lichenoid forms respond better
Localized and circumscribed GVHD respond Widespread sclerodermoid forms respond poorly Increments are done very slowly
URTICARIA PIGMENTOSA
TEMPORARY INVOLUTION Loss of Darier’s sign Relief of itching Flattening Complete disappearance of cutaneous
macules and papules
Histamine induced migraines and flushing also subsides with continued treatment
Gradually increasing doses to be administered to avoid degranulation of mast cells
PITYRIASIS LICHENOIDES
PUVA found to be beneficial NB UVB widely used though the
condition tends to remain persistent in some cases.
Conflicting reports
PARAPSORIASIS
Phototherapy is indicated for all types of parapsoriasis and its clinical variants.
Clearing of recalcitrant lesions as well as preventing evolution in to MF
PITYRIASIS RUBRA PILARIS
Some respond, others flare Some require combination with
retinoids or methotrexate
GRANULOMA ANNULARE
• Lesions found to resolve completely
• Relapse frequent• Long term maintenance required
LICHEN MYXOEDEMATOSUS
Papular lichenoid eruption and mucin deposition in the dermis
Paraproteinemia Histologically, the proliferation of fibroblasts is
enhanced in the dermis, and collagen bundles are split by mucinous infiltration
PUVA treatment has a suppressive effect on DNA synthesis and cell proliferation
ALOPECIA AREATA• Found to respond after a number of sessions• Cirscumscribed lesions respond better
compared to total alopcia• Follow up studies showed phototherapy not
very effective• Relapse is high
MORPHEA
Low dose ultraviolet A-1 phototherapy (UVA-1, 340–400 nm) has been shown to improve symptoms of morphea
Induce a marked softening of the skin Complete resolution of the thickened and
hyalinized collagen bundles Return to histologic features of normal skin
MECHANISM
Induction of interstitial collagenase (matrix metalloproteinase 1)
Release of singlet oxygen Release of signaling peptides such a
interleukin- 1a (IL-a), IL-1b, and IL-6 Release of hydrogen peroxide, which increases
mRNA levels of interstitial collagenase
Different types of phototherapy have been used
UV-A 1 found to be most effective Longer the wavelength greater the
penetration
PRURITUS
Renal Hepatic Aquagenic pruritus Aquagenic urticaria Chronic urticaria Hiv and eosinophilic folliculitis
PHOTODERMATOSES
Preventive treatment by producing hardening 3-4 weeks of PUVA sufficient to suppress the
disease PUVA induces pigmentation rapidly 10% report new lesions- no need to reduce
dosing 5- MOP preferred
REGULAR SUN EXPOSURES REQUIRED FOR MAINTENANCE
REMISSION FOR 2-3 MONTHS
EXTRACORPOREAL PHOTOCHEMOTHERAPY
Introduced in early 1980s for palliative treatment of CTCL
Immunomodulatory therapy that combines leukapheresis with phototherapy
Treat autoreactive or neoplastic disorders caused by aberrant clones of T lymphocytes
Patient’s blood is extracted and centrifuged to obtain the leukocyte concentrate
8-MOP is administered directly into the bag containing the leukocyte concentrate
The 8-MOP molecule enters the cell and its nucleus quickly
Exposed to UV-A radiation (1-2 J/cm2)
T-Cell Apoptosis Dendritic cells- blood monocytes
adhere to the plastic surface of the device, get converted to immature dendritic cells
Anti tumor response –CD 8 cells stimulate the TH1 response
PREDICTORS OF GOOD RESPONSE Erythroderma Less than 2 years since diagnosis Leukocyte count lower than 20,000/μL Presence of 10% to 20% circulating Sézary
cells Absence of palpable lymph nodes Absence of visceral involvement Absence of previous intensive chemotherapy High peripheral blood CD8 lymphocyte count
ADVERSE EFFECTS Headache Nausea Fever Muscle pain Hypotension Exacerbation of skin lesions after
treatment Vasovagal syncope Septicemia Injection site infection.
TARGETED THERAPY
ADVANTAGES
Exposure of involved areas only and sparing of uninvolved areas
Quick delivery of energy and thereby shortened duration of treatment
Delivery of higher doses (super-erythemogenic doses) of energy because uninvolved areas are not exposed
This has been claimed to shorten duration of treatment, leading to less frequent visits to clinic, and thereby lessen the inconvenience for the patient
The maneuverable hand piece allows treatment of difficult areas such as scalp, nose, genitals, oral mucosa, ear, etc.
Easy administration for children as delivery is hand-held
Targeted phototherapy machines occupy less space
EXCIMER LASER
Mixture of noble gas and a halogen “Excited dimmers.” Depth of penetration is shallow-very
precise action Ablative photodecomposition Pulsed wave lasers-they deliver a high
energy in a short time, rapidly breaking chemical bonds.
Overall treatment time is usually shorter Mean number of treatments and the
cumulative UV dose are significantly lower Lower therapeutic cumulative dose of the XeCl
laser involves a lower risk of carcinogenesis. This treatment option makes it possible to
selectively treat skin lesions and spares uninvolved skin
BALNEOTHERAPY
Bath water delivery of 8-methoxypsoralen (bath PUVA) or different salt solutions with a subsequent UVB- or UVA-irradiation
Bath PUVA has the advantage of selective and shorter photosensitization
no serious side effects Found to be efficacious compared to NBUVB
monotherapy
PHOTODYNAMIC THERAPY Kennedy, et al. in 1990 Destroy the desired target selectively 5-aminolaevulinic acid is the main agent used Actinic keratoses of the face and scalp Bowens disease Superficial basal cell carcinomas Acne
ULTRAVIOLET A1 THERAPY
o 340-400nmo Used as a tool for provocative testing
for PMLEo Photopatch testingo Treatment of several ultraviolet
responsive conditions
MECHANISM Induce T-cell apoptosis- atopic
dermatitis and MF Reduction in mast cells and Langerhan
cells Increase collagenase expression-
morphoea, keloid Tanninng- prophlaxis of PLE.
INDICATIONS
Atopic dermatitis PLE Morphoea
CTCL Follicular mucinosis Hand eczema Hypereosinophilic syndrome GVHD POEMS Keloids
HAND ECZEMA
Both local NB-UVB phototherapy and PUVA irradiation show similar beneficial responses.
Thick lesions UV-A preferred Studies show UV-A is better, more
penetration NB UV-B preferred in dry and
dyshidrotic types
SEBORRHEIC DERMATITIS
Many patients improve upon exposure to natural sunlight
Abnormal immunological response to the yeast or its degradation products may play an important pathogenetic role
Modulatory effect on inflammatory and immunological processes in the skin
A direct effect of UV irradiation on P. Ovale leading to ultrastructural changes and growth inhibition
Long standing cases and widespread involvement responded better
Relapse is common
ACNE VULGARIS
Porphyrins accumulated in the bacteria Propionibacterium acnes one of the etiologic factors involved in the pathogenesis, allows phototherapy to be a successful modality
Although blue light is best for the activation of porphyrins, red light is best for deeper penetration and an anti-inflammatory effect
RATIONALE
Porphyrins produced by P. acne Photothermal damage to the sebaceous
glands Anti-inflammatory effect
PHOTODYNAMIC THERAPY IN ACNE
Aminolevulinic acid (ALA)- taken up by the pilosebaceous units
Destruction of pilosebaceous units and killing of P.acne
ADVERSE EFFECTS
Discomfort Transient hyperpigmentation Exfoliative erythema Crust formation Photosensitivity
TO SUM UP…….
Good modality of treatment Alternative mode of management Relapse is common Carcinogen Cost of treatments