The Use of Chloroquine Diphosphate (Aralen) and Quinacrine (Atabrine) Hydrochloride in the Prevention of Polymorphous Light Eruptions

Abstract

The effectiveness of chloroquine diphosphate (Aralen) and quinacrine hydrochloride (Atabrine) in the treatment of lupus erythematosus has been demonstrated recently by several investigators (1, 2, 3, 4, 5, 6, 7, 8, 9). In addition, evidence has been offered that many polymorphous light eruptions are in reality subclinical (or latent) manifestations of systemic lupus erythematosus (10). Because of this relationship, we attempted to inhibit the development of polymorphous light eruptions (prurigo type) by the use of chloroquine and quinacrine. Sixteen patients (Skin and Cancer Hospital of Philadelphia, and the Hospital of the University of Pennsylvania) with the prurigo aestivalis type of polymorphous light eruption were included in this study. These patients gave a 2 to 19 year history of recurrent eruptions in the spring, summer and fall on the sun-exposed regions of the body. All had normal laboratory findings which included complete blood count, urinalysis, total protein, albumin-globulin ratio, sedimentation rate, and serologie test for syphilis. All patients were treated with either chloroquine or quinacrine and were cautioned to avoid sun-light exposure for three weeks. They were then allowed to go into the bright midday summer sunlight without topical protection. The following table indicates results obtained (Table I). DISCUSSION AND CONCLUSIONS The sixteen patients included in this preliminary study have the prurigo aestivalis type of polymorphous light eruption. The drugs, chloroquine diphosphate or quinacrine hydro-chloride, were administered in spring and early summer of 1953, when the eruptions were at their height. Following the disappearance of the eruptions while taking medication, fourteen of these sixteen patients had no recurrences for the remainder of the summer months despite unrestricted sun exposure. Local sun screening agents were not used. Several investigators (10, 11, 12, 13) have felt there may be periods of temporary refractoriness to the development of polymorphous light eruption on sunlight exposure, which alternate with phases of “sensitization.” Our work seems to indicate that chloroquine and quinacrine will successfully prevent polymorphous light eruptions in most cases. However, it will be necessary to determine to what extent a “refractory period” may be responsible for these apparently excellent results. Table I-pages 94 and 95 References-page 96 93 CO TABLE I Results of therapy in the prevention of polymorphous light eruption PATIENT SEX AGE 39 DURATION OF DISEASE. ERUPTION RECURRENT EACH SPRING AND SUMMER DRUG AND DOSE SIDE EFFECTS RESULTS COMMENT 1. F. L. Female 4 years Chloroquine, 2 weeks; 250 mg./day; then Quinacrine 100 mg. t.i.d. 4 weeks; then 100 mg./day. Papulo-squamous eruption, due to chloroquine (). (Chloroquine stopped.) Excellent No recurrence after intense sun-exposures, while taking Quinacrine. 2. A. H. Female 63 9 years Chloroquine 250 mg./day. None Excellent No recurrence after intense sun-exposures. 3. H. W. Male 45 8 years Chloroquine 250 mg./day. None Excellent No recurrence after intense sun-exposures. 4. V. S. Male 30 4 years Chloroquine 250 mg./day. None Partial protection only Mild recurrence after intense sun-exposure. 5. E. McM. Male 32 3 years Chloroquine 250 mg./day. None Excellent No recurrence after intense sun-exposures. 6. E. W. Female 40 10 years Chloroquine 250 mg./day f or 1 month, then 250 mg. 3 times a week. None Excellent No recurrence after intense sun-exposures. 7. E. C. Male 24 2 years Chloroquine 250 mg./day. None Partial protection only Mild recurrence after intense sun-exposures. - % tr O T 8. E. A. Female 34 5 years Chloroquine 250 mg./day for 2 months; then 250 mg. every other day. None Excellent No recurrence after intense sun-exposures. 9. H. 0. Female 29 7 years Chloroquine 250 mg./day for 7 weeks; then 250 mg. every other day. None Excellent No recurrence after intense sun-exposures. 10. A. 0. Female 38 3 years Chloroquine 250 mg./day. None Excellent No recurrence after intense sun-exposures. 11. C. L. Male 39 3 years Chloroquine 250 mg./day. None Excellent No recurrence after intense sun-exposures. 12. R. T. Male 58 2 years Chloroquine 250 mg./day for 6 weeks then 250 mg. 2 times a week. None Excellent No recurrence after intense sun-exposures. 13. G. C. Female 42 19 years Chloroquine 250 mg./day for 2 weeks; then 250 mg. every other day. None Excellent No recurrence after intense sun-exposures. 14. C. B. Male 42 2 years Chloroquine 250 mg./day for 4 days. Stopped 3 weeks; then Quinacrine 100 mg. t.i.d. Developed pruritus ani after taking Chloroquine 4 days. (Chloroquine stopped.) Excellent No recurrence after intense sun-exposures, while taking Quinacrine. 15. C. K. Male 39 6 years Chloroquine 250 mg./day. None Excellent No recurrence after intense sun-exposures. 16. S. S. Male 41 2 years Chloroquine 250 mg./day. None Excellent No recurrence after intense sun-exposures. 3 w O d O 96 THE JOURNAL OF INVESTIGATIVE DERMATOLOGY