[Phytophotodermatitis. Some photobiological aspects of psoralens]. / Fitofotodermatitis. Algunos aspectos fotobiológicos de los psoralenes.

The frequency of plant dermatitis, in general, depends on the type of plants, the climate, occupation and lifestyle of the local inhabitants. Many plants produce adverse effects on the skin like irritation, allergic reactions and phototoxicity. Generally, allergic contact dermatitis is emphasized but it is necessary to give more attention to phototoxicity produced by plants. The patients may be exposed not only to the phototoxic plant itself but also to its derivatives in perfumes, cosmetics and industry.

[Polymorphous light eruption: aspects of special interest]. / Erupción polimorfa lumínica: algunos aspectos de interés.

The authors make the revision of all the characteristic aspects of various clinical pictures which they consider to belong to the group of the Polimorphous Light Eruption. In this revision they include epidemiological, clinical, histopathological, differential diagnosis, pathogenical and terapeutical data.

[Polymorphic light dermatitis. Photobiology and photoprotection]. / Dermatitis polimorfa lumínica. Fotobiología y fotoprotección

It is possible in the majority of patients with polymorphic light eruption to produce lesions experimentally. Only the reproduction of the clinical reaction is significant for the diagnosis. Irradiation is carried out in the same test area two or three times with a dose of up to eight times the minimal erythema dose. Sunlight is the best agent for the evaluation of this protocutaneous disorder. A localised area of the skin can be exposed to midday sunshine about half an hour on three consecutive days. But sunlight has the disadvantage of having a variable ultraviolet emission at different times. It is necessary to differentiate lupus erythematosus and photocontact dermatitis, which may produce identical reactions. Other light sources are the hot quartz lamp, fluorescent tube "sun lamp", solar simulator and the monochromater. Patients with polymorphic light eruption are sensitive to light in the range 300 to 320 nm. but some of them are sensitive to savelengths shorter or longer than this range. The methods of protection against solar radiation which have been tried include: 1) Avoidance of sunlight; 2) Promotion of melanin hyperpgimentation and thickening of the stratum corneum-by controlled exposure to sunlight; 3) Application of a film of a chemical compound that will act as a physical screen and absorb, scatter or reflect damaging radiation; 4) Chemical modification of the stratum corneum by topically applied substances which can conjugate chemically or be absorbed onto the stratum corneum and filter the damaging rays. Many authors at present consider the use of alcoholic solutions of para-aminobenzoic acid (PABA) to be the most effective method of preventing reactions from exposure to sunlight. Pathak and Fitzpatrick showed that 5 % PABA in 70 % ethanol and 2,5 % Escalol 506 in 65 % ethanol is the most effective sunscreen against radiation of the sunburn spectrum. A dihydroxyacetone (DHA) and naphthaquinone (lawsone) sunscreen provides photoprotection for all types of photosensitivity throughout the whole UV spectrum even into the visible region. Systemic photoprotection: The administration of beta-carotene to patients with erythropoietic protoporphyria has resulted in amelioriation of their photosensitivity. Antimalarials are valuable therapeutic agents and are highly effective in controlling cutaneous lupus erythematosus, polymorphic light eruption and occasionally solar urticaria.

[Photodrugtherapy of psoriasis with oral psoralen and black light therapy]. / Fotoquimioterapia de la psoriasis con psoralene por vía oral y luz negra

Oral 4, 5', 8 trimethoxypsoralen (TMP) or 8-M-methoxypsoralen (8 MP) plus black light therapy of psoriasis produced disappearing of lesions in 6 out of 8 pacients treated with TMP and in 6 out of 7 treated with 8 MP. In three patients treated with the first drug, a paired comparision demonstrated that the ingestion of it, when followed of black exposure, is more effective than the exposure to conventional ultraviolet light. Parrish et al. have shown this for oral methoxalen and long wave ultraviolet light. Combined TMP or 8-MP and black light therapy inhibits epidermal DNA synthesis and this is the scientific base of its application in the therapy of psoriasis, disease in which an accelerated celular cicle and DNA synthesis has been postulated.

[Symptomatic or secondary allergic vasculitis. Pathogenesis of cutaneous vasculitis]. / Vasculitis alérgicas sintomáticas o secundarias. Patogenia de las vasculitis cutáneas

The histopathologic alterations of the allergic cutaneous vasculitis (fibrinoid necrosis of the walls of the small blood vessels with infiltration of neuthrophils in Karyorrexis) is seen in several entities. It is possible to divide such entities in two groups: a) Primitive allergic vasculitis in which the vascular lesion is dominant and. b) Secondary allergic vasculitis in which the vascular alterations, not constant, are integrants of variable histopathologic conditions. Many classifications have deen done on clinical and pathological bases. Such classifications are not satisfactory. A classification in base of physiopathologic and immunologic mechanisms could permit adequate therapeutic planning. In this paper we consider the secondary vasculitis only. The secondary angitis are seen in: 1) Difuse colagen diseases. 3) Conditions related to infections or inflamatory processes. 3) Angitis produced by drugs. 4) Conditions produced by insects or parasites bites. 5) Heterogeneous group that include diferent tipes of not necrotizing sistemic angitis in uhich, some times, trombosant and necrotizing processes are associated.