Bullous and haemorrhagic lichen sclerosus with scalp involvement

We describe a patient who developed a generalized blistering eruption due to lichen sclerosus and who was observed to have scalp involvement. Both are unusual manifestations of this disease which merit consideration. Lichen sclerosus is an uncommon disease that most frequently affects the external genitalia of perimenopausal women. The aetiology is unknown. Approximately 20% of affected patients have extragenital lesions that present as small, ivory, shiny round macules or papules that later become atrophic; extragenital lesions are generally asymptomatic. Bullous and haemorrhagic forms may occur but these are generally localized and reports of extensive or generalized involvement are rare. We describe an elderly woman with generalized bullous lichen sclerosus. As an incidental finding, she was observed to have lichen sclerosus affecting her scalp. This has rarely been described and it would appear that she is the third reported case of scalp involvement.     

Proliferative compartments in the normal nail unit

Summary The main distinction between the germinal matrix and the nail bed is that the former is the origin of all or most of the nail plate and the latter provides an epithelial surface to which the emerging nail can adhere. It has been argued that the nail bed may contribute substance to the nail plate and it is likely that if this was the case, epithelial proliferation in the nail bed would match that in the germinal matrix by a proportion appropriate to its contribution. We have measured the labelling index (LI) in the three major anatomical sites of the nail unit using Two antibodies to antigens expressed in cycling cells. Using Ki-67 (MIB-1) and proliferating cell nuclear antigen (PCNA) as markers of cell proliferation we have defined the LI in the germinal matrix (MIB-1: 22.1%. PCNA: 33%), nail bed (MIB-1: 0.75%, PCNA: 1%) and digit pulp (MIB-1: 16.8%, PCNA: 17.4%). This suggests a low degree of proliferation in normal nail bed consistent with a minimal or non-existent contribution to the nail plate. This may change in hyperkeratotic nail dystrophies, where the nail bed LI is raised (MIB-1: 31%, PCNA: 29%). illustrating how nail bed behaviour can alter with disease.     

Nail features in Langerhans cell histiocytosis

We report the case of an infant who presented with isolated cutaneous manifestations of Langerhans cell histiocytosis before the evolution of systemic features. In the transition period, at 9 months of age, nail unit changes became prominent, and persisted throughout the duration of systemic treatment. A change in clinical features coincided with a course of systemic gamma-interferon, which was given because immune paresis was suspected. Nail unit changes are rare in Langerhans cell histiocytosis. and this case illustrates the range of findings, including paronychia, nail fold destruction, onycholysis with subungual expansion, and nail plate loss. The significance of these changes as a prognostic indicator is controversial.     

Keratin expression in cutaneous lichen planus

The characteristic expression of keratins by keratinocytes is well documented. A typical 'hyperproliferative' profile of epidermal keratin expression occurs in psoriasis, wound healing and warts. This study analyses keratin expression in cutaneous lichen planus to determine abnormalities of differentiation occuring in this inflammatory disorder. Using a panel of monoclonal antibodies 28 samples (20 patients) were studied. The results showed that squamous differentiation was unaffected, with keratins K1 and K10 being expressed normally for the site sampled. The main abnormalities included extension of reactivity of the basal cell marker, LH8, into the suprabasal compartment. Keratin K17, usually restricted to adnexal structures, was variably expressed in the basal and suprabasal layers of the interfollicular epithelium of affected epidermis. Keratins K6 and K16, found suprabasally in hyperproliferative states, were detected both basally and suprabasally in all diseased samples. The keratin profile in lichen planus is analogous to the wound healing response. Suprabasal keratin K17 is found in psoriasis, wound healing and viral warts so the changes in keratin K17 may reflect hyperproliferative changes. It is likely that the changes in epidermal keratin expression are due to up-regulation of specific keratin genes by the production of cytokines and inflammatory mediators from the lymphocytic infiltrate typical of lichen planus.     

Pemphigus associated with nail dystrophy

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.     

Monilethrix: a clinicopathological illustration of a cortical defect

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.     

Spontaneous regression in angiocentric T-cell lymphoma

An 8-year-old boy presented with a 10-week history of ulcerating lesions which were histologically and immunocytochemically consistent with the diagnosis of angiocentric T-cell lymphoma. The disease was limited to the skin and resolved with no chemotherapy. Angiocentric T-cell lymphoma is commonly a disease with considerable morbidity and is often fatal. Epstein-Barr virus (EBV) could not be identified in involved tissue by immunostaining or by in situ hybridization. We consider whether the uncharacteristic absence of EBV in this case has prognostic significance.     

Normal sweat secretion rate in patients with alopecia areata

We have examined sweat secretion rates in 22 patients with alopecia areata, and 22 age- and sex matched controls. Mean sweat rate on the forearm in patients with alopecia areata was 20 mg/cm² per h (95% confidence limits 15–25 mg/cm² per h), and in controls was 24.1 mg/cm² per h (95% confidence limits 19.1–29.1 mg/cm² per h). Sweat secretion was higher in males than females in both the disease and control groups (27.8 mg/cm² per h [95% confidence limits 21.3–34.3 mg/cm² per h], compared with 18.08 mg/cm² per h [95% confidence limits 14.63-21.6 mg/cm²]; P > 0.01). Our results confirm the previously reported sex difference in sweat secretion rate, and demonstrate that there is no statistically significant difference between patients with alopecia areata and controls. We discuss our results in the light of a previous report claiming that patients with alopecia areata have reduced rates of cholinergic-induced sweating.     

A device for phototesting patients before PUVA therapy

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.