ULTRAVIOLET TREATMENT LAMP

Typical Number in Hospital: 5

Cost Bands: 3

References: 4

This produces electromagnetic radiation of wavelengths between 180 and 400 nm. For descriptive purposes the ultraviolet spectrum is divided into the following ranges:

UVA 315-400 nm

UVB 280-315 nm

UVC below 280 nm

The lamps are usually high-pressure mercury-quartz arc in a housing with a quartz window, cooled by either water flow or air blast. Fluorescent tubes are also available which produce light in the ultraviolet region.

They are mainly used in the treatment of diseases of the skin, tuberculosis, ulcerations, rheumatic conditions, and some childhood diseases. Vitamin D is produced in the skin in the presence of ultraviolet light and this effect has been used in the treatment of rickets in children. Ultraviolet light is toxic and needs to be monitored, particularly since the efficiency of the lamps decreases with time. The standard dose is the minimal erythemic dose or MED. This is the dose at which the skin shows a mild reddening 24 hours after the treatment.

A special type of mercury-vapour lamp used in the physiotherapy department is the Kromayer lamp which has a water- cooling system, and the rays actually pass through the water, so as to remove infrared radiation. The advantage of this type of lamp is that it can be applied directly to the area to be treated rather than operating remotely.