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Three siblings, 10, 9, and 5 years of age, developed a photosensitive disorder beginning in early childhood. In addition, the eldest of them developed a squamous cell carcinoma of the skin. The clinical and pathological pictures fit with the rare autosomal recessive disorder known as xeroderma pigmentosum (XP).
Skin fibroblasts from a patient with the photosensitive disorder hydroa vacciniforme were tested in vitro for DNA repair capacity. The rate of ultraviolet light (254 nm)-induced unscheduled DNA synthesis (UDS) in these fibroblasts was found to be 51-59% of the rate found in 4 normal fibroblasts strains. The patient had none of the clinical signs of the classic DNA deficient disease, xeroderma pigmentosum.
The authors describe a case of tinea faciei occurring in a sixteen-year-old boy. The rash was localized to the face and upper chest and resembled a typical photosensitive disorder, resulting in inappropriate treatment for six months. Results of a potassium hydroxide preparation and culture from the surface scale confirmed the clinical diagnosis.
Esophageal cancer is a tumor that, at diagnosis, is often advanced and not curable. In patients with good operative risk, surgery is still considered the ideal treatment. As many patients are elderly and have complicating serious medical conditions which preclude major resective surgery, endoscopic treatment (endoscopic oncology) has become a recent alternative. The endoscopic approach includes dilation, thermal destruction with Bicap probes, Nd. Yag laser, injection therapy, photodynamic therapy (PDT) and prostheses. This work is focused on photodynamic therapy which is safe but continues to be an experimental treatment. Its role in gastrointestinal malignancies is evolving. Currently the best results are to be expected in early lesions where the treatment could be curative.
Photoecological consequence of ozone holes are considered. Analysis of the total UV-radiation intensity and the short-wave edge of atmospheric transmittance depending on ozone content is presented. Characteristic times of some photodamages to skin and eyes have been estimated under ozone content reducing. A role of photosensitizers including drugs in phototoxical effects is discussed. Possible ways of photoprotection are considered.
The application of PDT in dermatology has been limited by technical problems, lack of standardized treatment parameters and controlled clinical trials, and cutaneous photosensitivity. PDT requires specially trained personnel and relies on devices that are expensive and difficult to maintain. In North America, PDT is currently performed at only a few centers on an investigational basis. Although a great deal of anecdotal clinical information is available on PDT for treating non-melanoma skin cancer, controlled trials are still needed in order to compare PDT with the highly effective methods already available. PDT may also be useful for a variety of nononcologic dermatoses. New photosensitizers such as BPD-MA, NPe6, and ALA offer the promise of causing significantly less prolonged photosensitivity than the currently available agents; combined with well-designed clinical studies, this will undoubtedly facilitate the acceptance of PDT into standard dermatologic practice.
Indomethacin inhibits UVB erythema but is thought not to influence UVA erythema. We have examined the wavelength dependence of the effect of indomethacin on ultraviolet radiation (UVR) erythema. Duplicate sites on the back were irradiated with a series of doses at 300 and 320 nm, or single doses at 330, 340, 350 or 370 nm. Indomethacin 1% was applied to sites on one side of the back after irradiation, occluded for 2h and erythema measured at 24h with a reflectance instrument. Indomethacin inhibited 300 and 320 nm (UVB) erythema, had no effect at 330 and 340 nm (UVA2), but augmented 350 and 370 nm (UVA1) erythema. There appears to be a varied response of UVR erythema to cyclo-oxygenase inhibition at different wavelengths across the UVR spectrum. This mechanism may be deranged in certain photosensitive disorders.
We have reviewed the data on unwanted side effects of drug therapy, as reported to the Norwegian Medicines Control Authority during the period 1970 to 1993. In all, 13,000 unwanted side effects were reported during this period. The number of recorded side effects was analysed especially in respect of unwanted reactions of the skin and appendages, and photosensitive reactions. 799 reported side effects involved the skin and appendages. Out of these, 64 reports (8%) were classified as being photosensitive reactions. Tetracyclines, diuretics and antihypertensive agents were the drugs most often causing photosensitive reactions, although several uncommon photosensitizing drugs were also reported. The actual risk of photosensitisation is discussed in the light of the prescriptions of these substances actually issued.
The aim of this investigation was to establish a new model for phototoxicity which is more advanced than the widely used cultures of yeasts, bacteria or cells of various origin, and at the same time to avoid animal testing. We studied the extraembryonal vasculature of the incubated hen's egg. This model was originally introduced by toxicologists as an alternative to the rabbit's eye irritation test (Draize test). In the photo hen's egg test, substances are applied to the embryo's yolk-sac blood vessel system at a non-toxic concentration and are irradiated with 5 J/cm2 ultraviolet A (UVA) (320-400 nm). Promethazine, haematoporphyrin, ciprofloxacin and 8-methoxypsoralen were tested in this system. Death of the embryo, membrane discoloration and haemorrhage are parameters for phototoxic damage, which were recorded during an observation period of 24 h. These well-known phototoxic substances induced pronounced damage of the yolk-sac membrane and blood vessels which was not found in the controls (test substance alone, UVA alone or untreated) using a 2 x 2 factorial test design. The photo hen's egg test serves as a valid screening model for substances supposed to be photosensitizers owing to a phototoxic mechanism.
BACKGROUND: Despite their relatively localized nature, the therapy for surgically unresectable cholangiocarcinomas has been largely unsuccessful. Photodynamic therapy is a promising technique for both curative and palliative treatment of this malignancy. The effectiveness of a potential new photosensitizer, mono-l-aspartyl chlorin e6 (NPe6), was compared with that of a traditional drug, hematoporphyrin derivative (HpD), in photodynamic therapy administered to a human cholangiocarcinoma model. METHODS: An established cholangiocarcinoma cell line was inoculated subcutaneously in the left back of male nude mice age 8 weeks. After a predetermined tumor size was reached, the mice were randomly assigned to either a control group or an experimental group. Experimental tumor-bearing mice received either HpD (5 mg/kg or 10 mg/kg) or NPe6 (2 mg/kg, 5 mg/kg, or 8 mg/kg) followed by photoradiation. HpD and NPe6 were administered intraperitoneally at 24 and 2 hours, respectively, prior to light exposure. Photoradiation was conducted using a xenon-mercury arc lamp with a 405-650 nm filter at a light flux of 80 J/cm2. Tumor response was assessed by serial tumor volume measurements. RESULTS: Control mice showed an estimated mean tumor volume doubling rate of 9.0 days. Triaxial tumor measurements correlated well with autopsy measurements (correlation coefficient = 0.9). Overall differences in tumor volume reduction were detected (P < 0.001) among the three groups: HpD, NPe6, and controls (photoradiation only, HpD only, or NPe6 only). The degree of tumor volume reduction was superior for dosages of NPe6 compared with all dosages of HpD (P < 0.05). Although a dose effect was detected (P < 0.05) for HpD and separately for NPe6, a consistent dose-response relationship was not observed for either. Inhibition of tumor regrowth was better for NPe6 compared with HpD. The depth of tissue injury was significantly increased (P < 0.05), by 67%, for 5-8 mg/kg of NPe6 compared with 5-10 mg/kg of HpD. The duration of cutaneous photosensitization was also decreased for NPe6 compared with HpD. CONCLUSION: Photodynamic therapy with HpD or NPe6 was effective inducing tumor regression in the cholangiocarcinoma model in this study. At the dosages studied, NPe6 appeared to induce greater tumor regression than HpD, with decreased tumor regrowth and duration of cutaneous photosensitization.
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Late-onset erythropoietic protoporphyria (EPP) is a rare complication of myelodysplastic syndrome (MDS) but has not been described in association with a myeloproliferative disorder (MPD). EPP is normally an inherited disorder characterized by photosensitivity that starts in early childhood and results from overproduction of protoporphyrin secondary to ferrochelatase (FECH) deficiency. Severe liver disease occurs in 1% to 2% of patients. Here we report that severe photosensitivity and cholestatic liver disease in a patient with a myeloproliferative disorder was caused by excess protoporphyrin production from a clone of hematopoietic cells in which one FECH allele had been deleted. Our observations suggest that the usual explanation for the association of late-onset EPP with MPD and MDS is acquired somatic mutation of one FECH allele in bone marrow and show for the first time that the consequent overproduction of protoporphyrin may be severe enough to cause acute liver damage.
The Smith-Lemli-Opitz syndrome has only recently been added to the small number of congenital disorders characterized by photosensitivity. The clinical features of this disorder are distinct from other photosensitivity syndromes. Details on the patho-mechanism of photosensitivity in the Smith-Lemli-Opitz syndrome have yet to be fully determined. However, preliminary evidence points to the deranged cholesterol metabolism that characterizes the syndrome as causal in this UVA-mediated photosensitivity disorder.
The term PIBI(D)S has been used to indicate a rare recessively inherited genetic disorder characterized by photosensitivity, mild non-congenital ichthyosis, brittle sulphur-deficient hair with trichoschisis (trichothiodystrophy), impaired intelligence, occasionally decreased fertility and short stature. To the best of our knowledge, about 20 cases have been reported in the literature. Here we report the characterization of the hair, brain, ultraviolet sensitivity and DNA excision repair defects of a new patient affected by PIBI(D)S. The diagnosis of PIBI(D)S syndrome was made in our patient on the basis of the clinical features and then confirmed by hair microscopy and biochemical analysis. Our patient has increased muscular tone, alteration of the deep tendon reflexes and psychomotor retardation, all consistent with hypomyelination of the brain showed by magnetic resonance imaging and computed tomography. A deficiency of DNA repair capacity was demonstrated in our patient. Furthermore, complementation analysis by cell fusion assigned our patient to xeroderma pigmentosum group D. The nucleotide excision repair defect of the other reported patients with PIBI(D)S falls generally into the same group as xeroderma pigmentosum group D and carry a mutation on the same repair gene (XPD). The relationship between these molecular characteristics and the clinical spectrum of PIBI(D)S is discussed.
Fraternal twins of Malay descent had the Rothmund-Thomson syndrome. This is a rare, autosomal recessive disorder characterized by photosensitivity, poikiloderma, short stature, skeletal defects, and juvenile cataracts. This is the first case report of the syndrome from southeast Asia.
BACKGROUND: Lymphocytic infiltration of the skin (LIS) is a disorder in which photosensitivity has been suspected but never proven. OBJECTIVES: To carry out a systematic photobiological investigation in patients with LIS and to compare the photobiological features of LIS with those of other photosensitive disorders. METHODS: We performed provocative phototesting with ultraviolet (UV) A and UVB in 10 patients with active LIS. RESULTS: In all patients, UVA and/or UVB elicited abnormal papular phototest reactions resembling lesions of LIS both clinically and histologically. Lesions typically developed 3--6 days (mean +/- SD 100.8 +/- 20.9 h) after the first UV exposure. CONCLUSIONS: This characteristic latency interval together with certain clinical features, i.e. onset in summer, predilection for the face and persistence of the lesions, indicate that LIS is a photosensitive disorder distinct from polymorphic light eruption but indistinct from lupus erythematosus (LE). Both our photobiological findings and the effective treatment with hydroxychloroquine in half of our patients strengthen the proposal that the two entities LIS and LE tumidus are identical. As diagnosis cannot be made by histological, immunofluorescence or laboratory criteria, provocative phototesting may be a diagnostic aid in this disorder.
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