Sparfloxacin-induced photosensitivity and the occurrence of a lichenoid tissue reaction after prolonged exposure

Drug-Induced Photosensitivity: Clinical Types of Phototoxicity and Photoallergy and Pathogenetic Mechanisms

Drug-induced photosensitivity (DIP) is a common cutaneous adverse drug reaction, resulting from the interaction of ultraviolet radiations, mostly ultraviolet A, with drugs. DIP includes phototoxicity and photoallergy. A phototoxic reaction is obtained when topical and systemic drugs or their metabolites absorb light inducing a direct cellular damage, while a photoallergic reaction takes place when the interaction between drugs and ultraviolet radiations causes an immune cutaneous response. Clinically, phototoxicity is immediate and appears as an exaggerated sunburn, whereas photoallergy is a delayed eczematous reaction. DIP may show several clinical subtypes. In this mini-review we report the pathogenetic mechanisms and causative drugs of DIP. We offer a detailed description of DIP clinical features in its classical and unusual subtypes, such as hyperpigmentation/dyschromia, pseudoporphyria, photo-onycolysis, eruptive teleangiectasia, pellagra-like reaction, lichenoid reaction, photodistributed erythema multiforme and subacute/chronic cutaneous lupus erythematosus. We described how physicians may early recognize and manage DIP, including diagnostic tests to rule out similar conditions. We made suggestions on how to improve sun exposure behaviors of patients at risk of DIP by means of an aware use of sunscreens, protective clothing and recent technologic tools. We highlighted the lack of sun safety programs addressed to patients at risk of DIP, who need a formal education about their condition.

Drug-Induced Photosensitivity-An Update: Culprit Drugs, Prevention and Management

Photosensitive drug eruptions are cutaneous adverse events due to exposure to a medication and either ultraviolet or visible radiation. In this review, the diagnosis, prevention and management of drug-induced photosensitivity is discussed. Diagnosis is based largely on the history of drug intake and the appearance of the eruption primarily affecting sun-exposed areas of the skin. This diagnosis can also be aided by tools such as phototesting, photopatch testing and rechallenge testing. The mainstay of management is prevention, including informing patients of the possibility of increased photosensitivity as well as the use of appropriate sun protective measures. Once a photosensitivity reaction has occurred, it may be necessary to discontinue the culprit medication and treat the reaction with corticosteroids. For certain medications, long-term surveillance may be indicated because of a higher risk of developing melanoma or squamous cell carcinoma at sites of earlier photosensitivity reactions. A large number of medications have been implicated as causes of photosensitivity, many with convincing clinical and scientific supporting evidence. We review the medical literature regarding the evidence for the culpability of each drug, including the results of phototesting, photopatch testing and rechallenge testing. Amiodarone, chlorpromazine, doxycycline, hydrochlorothiazide, nalidixic acid, naproxen, piroxicam, tetracycline, thioridazine, vemurafenib and voriconazole are among the most consistently implicated and warrant the most precaution by both the physician and patient.

Drug-induced photosensitivity: culprit drugs, management and prevention

Photo-induced drug eruptions are cutaneous adverse events due to exposure to a drug and either ultraviolet or visible radiation. Based on their pathogenesis, they can be classified as phototoxic or photoallergic drug eruptions, although in many cases it is not possible to determine whether a particular eruption is due to a phototoxic or photoallergic mechanism. In this review, the diagnosis, prevention and management of drug-induced photosensitivity are discussed. Diagnosis is based primarily on the history of drug intake and the clinical appearance of the eruption, primarily affecting sun-exposed areas of the skin. Phototesting and photopatch testing can be useful adjuncts in making a diagnosis. The mainstay of management is prevention, including informing patients of the possibility of increased sun sensitivity and the use of sun protective measures. However, once the eruption has occurred, it may be necessary to discontinue the culprit medication and treat the eruption with a potent topical corticosteroid. Drugs that have been implicated in causing photosensitive eruptions are reviewed. Tetracycline, doxycycline, nalidixic acid, voriconazole, amiodarone, hydrochlorothiazide, naproxen, piroxicam, chlorpromazine and thioridazine are among the most commonly implicated medications. We review the medical literature regarding evidence for the culpability of each drug, including the results of phototesting, photopatch testing and rechallenge testing.

Induction of eosinophil-infiltrating drug photoallergy in mice

BACKGROUND

Drug photoallergy is one of the highly incident adverse effects. Several different histological patterns have been recognized.

OBJECTIVE

To establish a murine model of the eosinophil-infiltrating type of drug photoallergy by using afloqualone (AQ), a representative photosensitive drug.

METHODS

AKR/J mice were sensitized by intraperitoneal injection of afloqualone solution (2mg/kg/mouse) and irradiation of shaved abdomen with ultraviolet A light (UVA) (12J/cm(2)). This sensitization procedure was repeated 2-12 times, and 3 days after the last immunization, mice were challenged by a subcutaneous injection of AQ solution and irradiation of the same site with UVA. The draining lymph node cells (LNCs) were used for transfer and cytokine production studies, and the challenged skin was analyzed for chemokine expression.

RESULTS

More than 10 times of sensitization induced a massive infiltrate of eosinophils and lymphocytes at the challenged site. AKR/J mice were a high responder strain. The sensitivity was transferred with 5-8 x 10(7) immune lymph node and spleen cells into naïve mice. CD4(+) T cells were mainly responsible for this sensitivity, since 1 x 10(7) CD4(+) cells alone induced a high level of sensitivity, but CD8(+) T cells evoked the sensitivity to a lesser degree. Culture supernatants from AQ-photoimmuned lymph node cells contained a higher level of IL-4 and lower interferon-gamma than those from mice immunized with dinitrofluorobenzene. Finally, the skin of AQ-photochallenged site exhibited high expression of CCL24/eotaxin-2, a chemokine for eosinophils.

CONCLUSION

It is suggested that eosinophilic drug photoallergy is mediated by sensitized Th2 cells and locally produced eosinophil-attracting chemokines.

Photo-onycholysis due to sparfloxacin

This paper describes a case of sparfloxacin-induced photodermatitis associated with photo-onycholysis in a 36-year-old man. He was being treated with sparfloxacin, streptomycin, ethambutol and pyrazinamide for pulmonary tuberculosis. He developed an exaggerated sunburn-like rash over the face and the dorsa of hands and feet, and painful onycholysis of finger- and toe-nails. Withdrawal of sparfloxacin resulted in resolution of the skin rash and nail tenderness.

A randomized controlled trial (volunteer study) of sitafloxacin, enoxacin, levofloxacin and sparfloxacin phototoxicity

BACKGROUND

Fluoroquinolone antibiotics (FQs) are associated with phototoxic skin reactions following exposure to sunlight.

OBJECTIVES

We aimed to compare the phototoxic potential of sitafloxacin, a novel FQ with three others: sparfloxacin, enoxacin, levofloxacin and placebo in Caucasian volunteers. In a second study, two dosage regimens of sitafloxacin were compared with placebo in Oriental subjects.

METHODS

Randomized, placebo-controlled, assessor-blinded clinical trial. In 40 healthy Caucasians, sitafloxacin 100 mg twice a day (n = 8), sparfloxacin 200 mg day-1 (n = 8), enoxacin 200 mg three times a day (n = 8), levofloxacin 100 mg three times a day (n = 8) and placebo (n = 8) were given in oral doses for 6 days. In the second study, sitafloxacin 50 mg and 100 mg, both twice daily, were compared with placebo in 17 healthy Oriental subjects. Using an established monochromator technique, baseline threshold erythema levels were established pre-drug and on-drug. The phototoxic index (PI) baseline, minimal erythema dose (MED) divided by on-drug MED for each medication at each wavelength was determined and related to sitafloxacin peak plasma levels. The duration of susceptibility to phototoxicity was assessed by repeat phototesting daily after stopping medication.

RESULTS

In the Caucasian study, sitafloxacin 100 mg twice a day produced mild ultraviolet (UV) A-dependent phototoxicity (median PI = 1.45) at 365 +/- 30 nm (half-maximum bandwidth), maximal at 24 h with normalization by 24 h postdrug cessation. The sparfloxacin group experienced severe phototoxicity maximal at 24 h and, unusually for an FQ, extended in the visible region (430 +/- 30 nm), maximal at 400 +/- 30 nm (median PI = 12.35) with abnormal pigmentation at on-drug phototest sites lasting, although fading, for up to 1 year. Enoxacin showed UVA-dependent phototoxicity (335-365 +/- 30 nm) median PI 3.94 (at 365 +/- 30 nm) returning to normal 48 h after stopping the drug. Fading pigmentation at phototoxic sites also lasted up to 1 year. Phototoxicity was not detected in the levofloxacin or placebo groups. In the Oriental study, no clinically relevant phototoxicity was seen with either sitafloxacin or placebo groups.

CONCLUSIONS

We conclude that 100 mg twice a day sitafloxacin in Caucasians is associated with a mild degree of cutaneous phototoxicity. Enoxacin 200 mg three times a day and sparfloxacin 200 mg day-1 are much more photoactive. Sparfloxacin phototoxicity is induced by UVA and visible wavelengths. Levofloxacin and placebo failed to show a phototoxic effect. In the Oriental study, sitafloxacin 50 mg twice a day and 100 mg twice a day failed to demonstrate a clinically significant phototoxic effect.

Melanocyte melanin augments sparfloxacin-induced phototoxicity

Quinolone has become one of the common causative agents of drug-induced photosensitive dermatitis, and its phototoxicity has now become a clinical issue. The mechanisms of long-lasting phototoxicity induced by sparfloxacin (SPFX) were investigated using melanotic and amelanotic melanoma cell lines. The sensitivities to SPFX and UVA irradiation up to 6 J/cm2 of both cells were not significantly different. However, the melanotic melanoma cell cultured with 1-150 microg/ml of SPFX showed significantly higher sensitivity to UVA irradiation compared with that of the amelanotic melanoma cell. By pulse culture with SPFX, the bound SPFX level of melanotic cell line was 10-20 times higher than that of the amelanotic cell line. These data strongly suggest that the melanin in melanocytes and keratinocytes accumulates the antibacterial quinolone and increases its tissue concentration in the basal epidermis and contributes to the long-lasting photo-injury and liquefaction degeneration of the basal cells in antibiotic quinolone phototoxic dermatitis.

Lymphocyte stimulation test with drug-photomodified cells in patients with quinolone photosensitivity

Quinolone antibacterial agents, known to elicit photosensitive dermatitis as an adverse effect, have both phototoxicity and photoallergenicity. The latter potency is mainly derived from their photohaptenic moiety; quinolones covalently bind to protein and cells upon exposure to ultraviolet A (UVA) light. Our previous study has shown the in vivo and in vitro antigenicity of quinolone-photomodified cells in mice. Here, we examined the presence of sensitized lymphocytes that react with quinolone-photomodified autologous cells in patients with photosensitivity to quinolones. A flow cytometric analysis using a monoclonal antibody specific to quinolone photoadducts demonstrated that peripheral blood mononuclear cells (PBMC) were successfully photomodified with quinolones upon exposure to UVA. PBMC from quinolone-photosensitive patients were cocultured with autologous PBMC photomodified with the causative drug. Modest but significant proliferative responses of responder lymphocytes were found in patients photosensitive to lomefloxacin, fleroxacin, and enoxacin, indicating photoallergic mechanism in these patients. On the other hand, sparfloxacin-photosensitive patients exhibited negative lymphocyte stimulation test, suggesting that its photosensitivity is mainly phototoxic. When UVA-preirradiated quinolones were used as stimulators, only fleroxacin exceptionally stimulated patients' PBMC, indicating its prohaptenic as well as photohaptenic properties. These findings suggest the presence of circulating sensitized T cells in patients with photosensitivity to certain quinolones.