Histiocytosis X in an elderly patient. Ultrastructure and immunocytochemistry after PUVA photochemotherapy.

The clinical features of a 76-year-old man with histiocytosis X of the Letterer-Siwe type, with extensive skin involvement, are described. The patient's lesions responded dramatically to PUVA-photochemotherapy. Light microscopic, immunocytochemical and immunoelectron microscopic findings, before and after PUVA, are reported. Birbeck granules in phagolysosomes of dermal macrophages indicated uptake of destroyed HX cells. Residual HX cells in the skin and HX cells in a recurring lesion expressed the same membrane antigens as in the primary lesions.

Phototherapy of urticaria pigmentosa: clinical response and changes of cutaneous reactivity, histamine and chemotactic leukotrienes.

Ten patients with moderate to very severe urticaria pigmentosa were studied for the therapeutic effect of photochemotherapy (PUVA; six adults) and selective ultraviolet phototherapy (SUP; four adolescents). Despite a high mean PUVA dosage (138.6 +/- 63.4 J/cm2), only two patients had a very good response, while three had a good response and one had a fair response. On the reduction of the frequency of treatments, the symptoms gradually recurred, and several months after the discontinuation of therapy, the clinical status had reached the level prior to PUVA. The results with SUP were even less encouraging. A number of biophysical and biochemical parameters of the skin were studied in five patients before PUVA treatment, immediately after several months of PUVA treatment and again 5 months after the discontinuation of PUVA treatment. Weal and erythema reactions to intracutaneous skin tests remained unchanged after PUVA, while wealing with topically applied dimethylsulfoxide (DMSO) decreased. Transepidermal water loss was markedly reduced over DMSO weals. Histamine levels, which were elevated in lesional but not in normal skin, dropped with PUVA treatment, but after the discontinuation of treatment, they increased again in the lesions. On reverse-phase high-performance liquid chromatography, two main chemotactic factors, leukotriene B4 and 5-HETE, were identified in lesional skin. Chemotactic activity was elevated in both lesional and uninvolved patient skin, reached normal levels at both sites after PUVA and maintained these low levels for several months after the discontinuation of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Response of cutaneous mast cells to PUVA in patients with urticaria pigmentosa: histomorphometric, ultrastructural, and biochemical investigations.

In six patients with urticaria pigmentosa, population density and ultrastructure of the cutaneous mast cells and histamine levels of the lesional skin were studied before, immediately after, and again 5-8 months after photochemotherapy (PUVA). Immediately after PUVA, the total mast cell number was not reduced, but on separate analysis of the intradermal distribution, significantly fewer mast cells were found in the papillary dermis and correspondingly more mast cells in the adjacent upper dermis. On electron microscopic examination, 4% of the mast cell granules were immature before and 27% after PUVA therapy, based on the lower electron density of the granular matrix. This was associated with a markedly lower histamine content of the lesional skin. Five to eight months after recovery from PUVA, the morphologic changes and the histamine levels had all returned to the pre-PUVA status. These findings were paralleled by a reversal of all clinical beneficial effects that had been observed with PUVA.