No abstract

No abstract

We describe two sisters aged 2 and 7 years, with monilethrix. The older sister was clinically less severely affected but, microscopically, the features of weathering and alternating nodes and internodes were more obvious. The younger girl had more severe alopecia, with shorter hair, but the microscopic features were less marked. Scanning-electron microscopy demonstrated only slight cuticular weathering in both cases, and evidence of breakage in the cuticle at points of no obvious cuticular pathology. Transmission-electron microscopy showed normal cuticle cells in cross-section, but an abnormal cortex. The abnormalities included areas of homogeneous non-fibrillar material, and a deviated axis of some microfibrils. We consider that these findings support the possibility that a cortical defect contributes significantly to the fragility of hair in monilethrix. This might explain why hair with marked beading can be stronger than hair from an affected sibling with less apparent abnormality.

A device is described and validated for rapid and easy phototesting of patients at the start of a course of PUVA therapy. The phototesting template consists of metal foil with four apertures of 10 mm diameter, mounted in pliable polyurethane. One aperture is open, and the other three each incorporate a grid of hexagonal holes of differing size which attenuate the radiation, resulting in relative intensities at the skin surface of 1, 2, 4 and 8. Thus, a single exposure through the foil of, for example, 8 J/cm2, would allow the minimal phototoxic dose to be determined as either 1, 2, 4, 8, or > 8 J/cm2. The device was validated by comparison with a metal foil with four open apertures, but otherwise identical construction, in which the dose was controlled by varying the exposure time. In 11 subjects, tested with one device on each arm, the minimal phototoxic dose, judged visually, was identical. Reflectance measurements of erythema at each of the test sites showed no systematic difference between the two methods. The device has no moving parts, requires no source of electrical power, will not change its optical transmission with age, and is robust and easy to use. It should, therefore, allow much wider application of the useful technique of minimal phototoxic dose determination before PUVA therapy.

A new association is described between reacting perforating coUagenosis and Down s syndrome in a child with lupoid hepatitis.