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Notes: Three possible mechanisms of the hair shaft abnormality in cheveux incoiffables have been investigated in nine patients. Cheveux incoiffables hairs were found to exhibit a normal distribution of cystine-rich protein within both the cuticle and the cortex, as determined by silver methenamine ultrastructural cytochemistry. Resistance to stretching, at 65% relative humidity and constant temperature, was similar to normal controls. Resistance to bending forces was also assessed, and was equivalent in both groups. On scanning electron microscopy, all patients with cheveux incoiffables demonstrated longitudinal grooving of the hair shaft, and the hairs were triangular or heart-shaped in cross-section. In addition, there appeared to be minimal cuticular weathering. Even hairs of 20–30 cm length showed only minimal cuticular and cortical weathering, compared with normal hair shafts of similar length and diameter. It is possible that the reduced progressive weathering renders the hair shaft more rigid, and could serve to explain the ‘stand on end’ appearance of the hair which is typical of this condition. However, the characteristic cross-sectional shape of the hair shaft in cheveux incoiffables may render it more rigid and resistant to bending forces. This latter theory has yet to be fully investigated.

Notes: The anatomy of the epidermis, dermis and subcutaneous tissues of the nail apparatus is distinct from that of non-appendageal skin. Apart from the demonstration of the longitudinal configuration of the dermal-epidermal junction of the nail bed, there have been no studies of the composition of the basement membrane zone of the nail apparatus. We obtained three human accessory digits, including one thumb, all of which had been amputated for cosmetic reasons, and were without known pathology. Specimens were stained with a battery of monoclonal and polyclonal antibodies which target normal basement membrane zone antigens, and studied by indirect immunoflourescence.This study demonstrated that the four distinct regions of the nail, namely the proximal nail fold, the nail matrix, the nail bed and the hyponychium expressed all the target antigens found in the normal non-appendageal basement membrane. In particular, there was normal expression of the epidermal-associated antigens, the 220-and 180-kDa bullous pemphigoid antigens, and the α6β4 integrin. There was also normal expression of the lamina lucida antigens LH39, GB3 and laminin. It is of interest that the dermal-associated components, namely the 285-kDa linear IgA antigen, the extracellular matrix glycoproteins chondroitin sulphate, type VII collagen and its closely associated proteins, and the poorly characterized antigen for LH24 and LH39 were all normally expressed.Fibronectin, which is not a normal basement membrane zone component, was diffusely expressed in the extracellular matrix, but did not accentuate the basement membrane zone. LHF2, an antibody raised against tenascin, which shows weak positive staining at the tips of dermal papillae in normal skin (unpublished data) diffusely stained the extracellular matrix and the tips of the dermal papillae of the nail matrix and hyponychium, but did not stain the basement membrane of the nail bed.These findings show that despite the numerous distinct features of epidermis, dermis and subcutis of the nail apparatus, the basement membrane zone has virtually identical antigen expression to that of the dermal-epidermal junction elsewhere. The difference in LHF2 expression in the nail bed most likely reflects the different shape of the nail bed basement membrane, which is arranged in longitudinal folds.

Notes: Two patients suffering from pemphigus vulgaris were found to have nail dystrophies which antedated the onset of mucocutaneous lesions by many years. The nail changes improved substantially on treatment of the bullous disease. One patient had nail matrix histology consistent with pemphigus, and both had positive direct immunofluorescence with intercellular IgG in the matrix epithelium, as well as at other body sites. We propose that dystrophic nails, as a non-specific indicator of autoimmune disease, are a genuine and relevant finding in pemphigus.

Notes: We have studied 10 cases of scarring alopecia, and investigated tbe diagnostic reliability of immunofluorescence and bistopatbology in licben planopilaris and pseudopelade. In tbe ligbt of our findings, we discuss tbe possible patbomechanisms of botb disease processes.

Notes: 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 moniiethrix. This might explain why hair with marked beading can be stronger than hair from an affected sibling with less apparent abnormality.

Notes: The clinicopathological features of the scarring alopecia of discoid lupus erythematosus (DLE) were studied. Scarring alopecia was present in 34% of 89 patients with DLE and was associated with a prolonged disease course. More than half these patients had scalp involvement at the onset of the disease. There was a significant reduction in size of sebaceous glands in affected scalp. Perifollicular lymphocytic inflammation was maximal around the mid-follicle at the level of the sebaceous gland, which seems to be an important functional level in the follicle. There are changes in the expression of the matrix molecules, the proteoglycans, in the connective tissue sheath and the keratin intermediate filaments in the outer root sheath cells at this level in normal scalp and in diseased scalp. Loss of a population of mid-follicular stem cells may be important in the pathogenesis of scarring alopecia in DLE.

Notes: We present a new case of irreversible hair matting, a rare, but important and alarming, acquired hair disorder. This case was investigated to test the causal hypothesis proposed in 1984. At the same time four other specimens of matted hair from patients and tangles from normal individuals were also examined. Light and electron microscopy showed dramatic permanent twisting and bending of the hairs through 180°. There was marked variation in the fibre width of hairs from matted samples, with some longitudinally split along a considerable length. This bending and entanglement of hairs of varying widths (felting) seemed to be the main reason for the hairs becoming so dramatically knotted together in four of the cases. In only one case was there any evidence of a viscous fluid binding the hair together. This finding suggests that there may be two different mechanisms involved in hair matting.