The effect of inositol supplements on the psoriasis of patients taking lithium: a randomized, placebo-controlled trial.

BACKGROUND: Lithium carbonate is the most widely used long-term treatment for bipolar affective disorders, but its ability to trigger and exacerbate psoriasis can become a major problem in patients for whom lithium is the only treatment option. Inositol depletion underlies the action of lithium in bipolar affective disorders and there are good theoretical reasons why the use of inositol supplements might be expected to help this group of patients. OBJECTIVES: To determine whether inositol supplements improve the psoriasis of patients on lithium therapy. METHODS: Fifteen patients with psoriasis, who were taking lithium, took part in a randomized, double-blind, placebo-controlled, crossover clinical trial comparing the effect of inositol supplements with those of a placebo (lactose). Changes in the severity of their psoriasis were measured by Psoriasis Area and Severity Index scores recorded before and after the different courses of treatment. The effect of inositol supplements on the psoriasis of 11 patients who were not taking lithium was evaluated in the same way. RESULTS: The inositol supplements had a significantly beneficial effect on the psoriasis of patients taking lithium. No such effect was detected on the psoriasis of patients not on lithium. CONCLUSIONS: The use of inositol supplements is worth considering for patients with intractable psoriasis who need to continue to take lithium for bipolar affective disorders.

Osler and the skin.

William Osler was the greatest physician of his time. Specialists reading his textbooks agreed that in their own specialities he was accurate and illuminating. His grasp of dermatology was particularly striking and skin changes are prominent in five of the syndromes named after him and in at least 100 of his papers. This paper describes how his early training in dermatology under Tilbury Fox in London and Hebra in Vienna combined with his unusual personal qualities to enable him to make massive contributions to a wide variety of dermatological topics. These include smallpox, cutaneous tuberculosis, nail growth, leprosy, scleroderma, pigmentation and purpuric eruptions as well as the more obvious hereditary haemorrhagic telangiectasia, angio-neurotic oedema and Osler's nodes.

Some observations on the direction of scratch marks.

This study consists of two parts. In the first we recorded 1696 scratch marks seen on 69 pruritic patients. The scratch marks followed a consistent pattern on the skin, which was independent of the cause of the itching. The most striking feature was a longitudinal alignment on the limbs. Next we tried to relate our findings to experimental work that suggests that itching is extinguished most effectively by counterstimuli applied within the same dermatomal segment. If this is the case, sufferers from itchy skin diseases might be expected to scratch itchy points on their skin using strokes directed along dermatomal lines, thereby gaining maximal relief. We used the data obtained during the first part of our study to test this possibility. Fifty-one percent of the scratch marks analyzed ran at an angle of less than 20 degrees to the nearest interdermatomal line (significantly higher than the 22.5% expected by chance). However the tendency for scratch marks to run along dermatomal lines was confined to the limbs. In addition, the preferred scratch directions of a group of nonitchy subjects, not driven by the need to alleviate actual itching, coincided closely with the pattern of scratch marks seen on the itchy patients. The direction of scratch marks may therefore be determined as much by mechanical factors affecting the ease of scratching as by the distribution of dermatomes.

How should we define itching?

The standard definition of itching (as "an unpleasant sensation that provokes the desire to scratch") takes no account of recent advances in knowledge about itch physiology. Always imprecise, this definition is also out-of-date. Its defects are discussed in this article, and some modifications are proposed.

Nocturnal scratching and its relationship to the disturbed sleep of itchy subjects.

This study of the relationship between nocturnal scratching and sleep is based on an analysis of 17 overnight polygraphic records of the scratch bouts and EEG of severely itchy patients. Our patients spent little time in deep orthodox sleep (stages 3 and 4), which was absent from 7 of the 17 records. Bouts of scratching were found to occur in all stages of sleep but were most numerous in stage 1 (light orthodox sleep). Sleep tended to remain stable, i.e. in a single sleep stage, for the 40 s immediately before a bout of scratching but had often changed to a more superficial stage by the time the bout had ceased, implying perhaps that scratching itself was the event linked most closely with arousal.