Puva bath therapy

• PUVA full bath: Full bath in 150 l bath water. For the addition, 15 ml of the 0.5% Methoxsalen (8-MOP solution) are pipetted off, dissolved in water at approx. 50 °C, then the bath is filled up to 150 l. The Methoxsalen bath water concentration is thus 0.5 mg/l.
• Alternatively: full bath with trimethylpsoralen 0.33 mg/l bath water: bath time of 20 min. at water temperature of 37 °C. Head (and hands) are not included. Immediately after the bath, irradiation with UVA is carried out, because already after 30 min. the MPD has risen again to approx. 50% and after 60 min. to 80% of the initial value, i.e. rapid decrease of the photosensitization!
• Foil bath: The application of PUVA foil baths is described. The patient takes a bath wrapped in a foil in a bathtub filled with warm water. 4 l of the diluted Methoxsalen solution are added to the inside of the foil. Under the pressure of the bathtub water, the foil fits closely to the body and distributes the Methoxsalen solution evenly over the surface of the body. Advantage: The amount of Methoxsalen solution per bath is reduced from 150 to 4 l. Disadvantage: Complex procedure.
• PUVA shower bath: 5-10 minutes shower with a recirculating shower system (e.g. Balneoplus) and trimethylpsoralen (0,20-0,30 mg/l shower water).
• Irradiation after full bath or shower: First dose after MPD, usually starting with 0.2-0.3 J/cm2 (depending on skin type), always keep the same time interval in the individual sessions.

Notice!

• Local PUVA treatment (hand or foot bath): 5 litres of bath water with the addition of 1 ml of the 0.5% Methoxsalen stock solution R161. Bath water concentration: 1 mg/l., bathing time 20 min. at 37 °C.
• Irradiation of hands or feet: Irradiation is done directly after the bath with UVA. Always keep the same time interval in the individual sessions!
  Avoid long intervals between bath and irradiation! 30 min. after the Methoxsalen bath, the MPD rises again to approx. 50%, after 60 min. to 80% of the initial value. Initial dose after determination of the MPD, usually 0.5 J/cm2. UVA dose increases, usually by 0.3-0.5 J/cm2 after every 3rd irradiation. Frequency of irradiation 3-4 times/week. After healing, if necessary maintenance therapy 2 times/week for max. 4 further weeks.

Remember! Due to delayed phototoxicity UVA dose increases after 72 hours at the earliest.

Notice! Patients must be well informed about increased sensitivity to light in the treated areas!

1. Karrer S et al (2001) Phototherapy of psoriasis: comparative experience of different phototherapeutic approaches. Dermatology 202: 108-115
2. Kerscher M et al (1994) PUVA bath therapy. Indications and practical implementation. dermatologist 45: 526-528
3. Leiter U et al (2002) Psoralen plus ultraviolet A-bath photochemotherapy as an adjunct treatment modality in cutaneous chronic graft versus host disease. Photodermatol Photoimmunol Photomed 18: 183-190
4. Loffler H et al (2002) Changes in skin physiology during bath PUVA therapy. Br J Dermatol 147: 105-109
5. Tanew A (2001) Correlation between 8-methoxypsoralen bath-water concentration and photosensitivity in bath-PUVA treatment. J Am Acad Dermatol 44: 638-642
6. Tegeder I et al (2002) Time course of 8-methoxypsoralen concentrations in skin and plasma after topical (bath and cream) and oral administration of 8-methoxypsoralen. Clin Pharmacol Ther 71: 153-161
7. Vallat VP et al (1994) PUVA bath therapy strongly suppresses immunological and epidermal activation in psoriasis: a possible cellular basis for remittive therapy. J Exp Med 180: 283-296