DefinitionThis section has been translated automatically.
Local or systemic application of methoxsalen (= psoralen; tricyclic furanocoumarin) for photosensitization with subsequent UVA irradiation. Methoxsalen (8-Methoxypsoralen; 8-MOP) or trimethylpsoralen (TMP) are mainly used. These are deposited in the cutaneous DNA and form non-covalent bonds (intercalation). By irradiation with long-wave UV light (UVA, 320-400 nm) at an action maximum at approx. 355 nm, the psoralens enter into a covalent bond with pyrimidine bases (especially thymine).
EffectsThis section has been translated automatically.
- Reduction of allergic late type reactions by reducing the number of Langerhans cells in the epidermis and thus reducing contact sensitization.
- Reduction of keratinocyte proliferation.
- Reduction of markers of epidermal activity such as keratin 16 or TGF-α.
- Reduction of immunologically active proteins expressed by keratinocytes (HLA-DR, ICAM-1, IP-10), which are held responsible for the interaction with T-lymphocytes in psoriasis, for example.
- Suppression of epidermal and dermal lymphocyte count and lymphocyte activity (CD3+, CD4+, CD8+, IL-2 receptor+), also in vivo.
- Effect on cytokines (TGF-α, IL-2, IL-6, IL-8, TNF-α, IFN gamma) and on molecules which can directly promote hyperproliferation of the epidermis (e.g. EGF, IGF-1, IL1 receptors, see growth factors below).
- Inhibition of DNA synthesis, increase in the rate of sister-chromatide exchange and increase in chromosome aberrations.
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IndicationThis section has been translated automatically.
Possible indications are:
- alopecia areata
- Eczema: Dermatitis, hypereosinophilic; eczema, atopic (except photoaggravated atopic eczema); eczema, contact allergic (hand and foot eczema); eczema, hyperkeratotic-rhagadiform hand and foot eczema.
- Graft versus host disease (acute and chronic forms)
- annular granuloma
- lichen planus
- Mycosis fungoides or cutaneous T-cell lymphoma in stages 1a, 1b and possibly 2a
- Papulose, lymphomatoid
- Pityriasis lichenoides (acute and chronic form), Pityriasis rubra pilaris
- Photodermatoses (hardening with systemic PUVA therapy or PUVA bath therapy) e.g.: reticuloid, actinic; light reaction, persistent; light dermatosis, polymorphic; dermatitis, chronic actinic; light urticaria, Hidroa vacciniformia
- protoporphyria, erythropoietic
- Prurigo shapes
- Psoriasis vulgaris, psoriasis (pustulosa) palmoplantaris
- Scleroderma, circumscripts
- urticaria pigmentosa
ImplementationThis section has been translated automatically.
- Systemic intake of Methoxsalen: see below PUVA therapy, systemic.
- Local application of Methoxsalen: see below PUVA Bath Therapy.
- First treatment dose 50-70% of the MPD or standard regimen according to skin type (see below the respective treatment types). Continuation of treatment 2-4 times/week.
- No erythema and good response: increase the UVA dose by 30% twice a week.
- Minimal erythema: no increase in UVA dose.
- Persistent asymptomatic erythema: no increase.
- Persistent symptomatic erythema (painful with or without edema or blistering): no further treatment until the symptoms subside.
- Resumption of treatment: After the symptoms have subsided, reduction of the last dose by 50%, further increases of 10%.
Undesirable effectsThis section has been translated automatically.
- Acute 1st to 2nd degree burns with overdose, itching, nausea. If eye protection is missing, keratitis photoelectrica.
- Chronic radiation damage to the skin: The most important long-term side effect of PUVA therapy is spinocellular carcinoma. After about 200-300 treatments, a significant increase in the skin tumour rate (primarily spinocellular carcinomas, hardly any basal cell carcinomas; no malignant melanomas!) by a factor of about 10-12 has been described. Further described are elastosis actinica; lentigines; melanoma, malignant, lentigo-maligna melanoma; basal cell carcinoma; testicular carcinoma in men (gonad protection!), questionable cataract formation (eye protection!).
ContraindicationThis section has been translated automatically.
- Increased risk of carcinoma: history of arsenic, pretreatment with ionising radiation, malignant skin tumours or dysplastic pigment moles, use of immunosuppressive drugs.
- Increased photosensitivity: intake of photosensitizing drugs such as: tetracyclines, sulfonamides, diuretics. External use of photosensitizing substances such as tetracyclines, benzoyl peroxide, St. John's wort oil.
- Photosensitive dermatoses: Herpes simplex infection, dermatomyositis, lupus erythematosus, photosensitive genodermatoses, photoaggravated endogenous eczema.
- Especially in the case of oral PUVA treatment: severe liver and kidney damage (if necessary, consult an internist).
- Especially during PUVA bath/shower treatment: cardiovascular problems, open wounds.
- Other: Pregnancy, lactation, children under 12 years.
Note(s)This section has been translated automatically.
- The UVA initial dose depends on the individual sensitivity to the phototoxic reaction, which is defined by the minimum phototoxic dose ( MPD).
- An increased risk of lymphoma in psoriatic patients after PUVA therapy does not seem to exist. On the other hand, the risk is increased in patients who simultaneously received a high cumulative dose of methotrexate.
LiteratureThis section has been translated automatically.
- Diederen PV et al (2003) Narrowband UVB and psoralen-UVA in the treatment of early-stage mycosis fungoides: a retrospective study. J Am Acad Dermatol 48: 215-219
- Farr PM et al (1984) PUVA treatment of scleromyxoedema. Br J Dermatol 110: 347-350
- Friedmann PS (1981) Disappearance of epidermal Langerhans cells during PUVA therapy. Br J Dermatol 105: 219-221
- Girbig P et al (1988) Special late effects in PUVA patients. Act Dermatol 15: 28-31
- Hölzle E et al (2003) Recommendations for phototherapy and photochemotherapy. SDDG 1: 985-995
- Honigsmann H (2001) Phototherapy for psoriasis. Clin Exp Dermatol 26: 343-350
- Ibbotson SH et al (2001) The effect of methoxsalen dose on ultraviolet-A-induced erythema. J Invest Dermatol 116: 813-815
- Kwok YK et al (2002) Psoralen photochemotherapy (PUVA) is only moderately effective in widespread vitiligo: a 10-year retrospective study. Clin Exp Dermatol 27: 104-110
- Stern RS (2006) Lymphoma risk in psoriasis: results of the PUVA follow-up study. Arch Dermatol 142: 1132-1135
- Stern RS et al (1990) Genital tumors among men with psoriasis exposed to psoralens and ultraviolet A radiation (PUVA) and ultraviolet B radiation. N Engl J Med 322: 1093-1097
- Wolff K (1985) PUVA Pro and Contra. dermatologist 36: 25-33