THE CHANGING PATTERN OF TOPICAL DERMATOLOGICAL THERAPY 665 ECZEMA Table II shows the analysis of prescriptions for patients suffering from eczema in 1951, 1957 and 1967. The most notable change is, of course, the increasing use of corticosteroids which were included in over 50}/o of the prescriptions in 1967. A welcome feature to the pharmacist is the declining use of dyestuffs in dermatology. Dispensing for dermatology clinics twenty years ago was a colourful activity with crystal violet dominating the scene. The figures also indicate a declining use of coal tar in prescriptions for eczema whilst it has continued to hold a useful role in the treatment of psoriasis. Table II Analysis of prescriptions for eczema Percentage of prescriptions Medicament , ,, 1951 1957 1967 Salicylic acid 7 0 6 Tar 40 22 3 Emulsifying ointment 0 20 10 Phenol 7 3 0 Crolamiton 0 0 10 Tannin 7 9 0 Mercury salts 14 22 0 Dyes 20 3 0 Zinc salts 20 33 6 Potassium permanganate 7 0 3 Ichthammol 14 9 3 Lead 14 0 0 Corticosteroids 0 6 53 Antibacterial agents 0 9 3 Antibiotics 0 0 6 With the exception of zinc, which is still commonly used as the oxide or carbonate, metallic salts are used to a lesser degree in topical dermatology. Mercury was formerly commonly used as the chloride, oxide and oleate but is now seldom prescribed except as ammoniated mercury chloride. Lead acetate which was frequently prescribed in lead lotion is no longer a feature of dermatological prescribing. The action of these highly toxic substances was always doubtful and they have been replaced by safer and more effective treatments. The use of ichthammol is also declining. This material is of uncertain composition and as a consequence, it not infrequently gives rise to diffi- culties in formulation, as for example when combined with zinc cream.

{3(•3(• JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Different batches of material, whilst complying with the official monograph, may nevertheless possess vastly different physical properties. It is difficult therefore to provide standard formulations which will produce satisfactory products on all occasions. It is, perhaps, a relief to the compilers of official formularies and pharmacopoeias that the demand for ichthammol in dermatology appears to be on the decline. PSORIASIS Table III shows the analysis of prescriptions for patients suffering from psoriasis over the same period. A notable feature again is the use of topical corticosteroids xvhich amounted to 50% of the prescriptions analysed in 1967. The early anti-inflammatory steroids showed little promise in the topical treatment of psoriasis. Cortisone acetate itself was without activity when applied locally to the skin whilst hydrocortisone was found to be beneficial in eczematous conditions but disappointing in the treatment of psoriasis. It was not until more potent, fluorinated steroids were introduced that local treatment of psoriasis became possible. Triamcinolone acetonide Table III Analysis of prescriptions for psoriasis Medicament Salicylic acid Mercury salts Zinc salts Sulphur [chthammol Corticosteroids Dithranol Tar Percentage of prescriptions 1951 1957 26 33 17 11 12 5 8 5 8 0 0 0 4 20 20 27 1967 2O 3 3 0 0 5O 6 22 was introduced in 1958 and was found to have a suppressive action in some cases of psoriasis. Later, fluocinolone acetonide was used and largely displaced triamcinolone. Betamethasone valerate was a further addition to the range of potent corticosteroids for topical application. Since then, a number of other fluorinated steroids have been added to the range, but fluocinolone acetonide and betamethasone valerate remain the two most commonly used compounds. The use of occlusive dressings in association with topical application has further extended the usefulness of the steroids in the treatment of psoriasis, although the increased skin penetration