RESUMEN
BACKGROUND: Previous studies have shown that oral PUVA is effective in urticaria pigmentosa. Long-term results, however, are unknown. OBJECTIVE: We studied the long-term effectiveness of oral PUVA treatment in urticaria pigmentosa as well as in systemic mastocytosis. In addition, the success of bath PUVA was examined in these diseases. METHODS: Twenty patients with urticaria pigmentosa and systemic mastocytosis treated by oral PUVA were examined retrospectively for a time period of up to 18 years. We studied the duration of improvement and correlated these results with the total PUVA dose, the skin type and the age of onset. Four patients were treated by bath PUVA therapy. RESULTS: In oral PUVA therapy an improvement was seen in 14 out of 20 patients (70%). There was no difference in the response rate between urticaria pigmentosa and systemic mastocytosis and there was no correlation with the total PUVA dosage. The duration of the treatment's success ranged from a few weeks to more than 10 years. 25% of the patients showed an improvement for more than 5 years. Patients with onset during childhood and early adolescence and patients with skin types I and II responded favourably to the treatment. Bath PUVA therapy was without effect in our 4 patients. CONCLUSION: Oral PUVA is very effective for the long-term treatment of urticaria pigmentosa as well as systemic mastocytosis.