Lymphocyte subsets and Langerhans cells in allergic and irritant patch test reactions: histometric studies

This study has attempted to distinguish between allergic and irritant reactions to patch tests by semiquantitative histological methods. The extent of perivascular chronic inflammatory infiltrate at 72 h in irritant patch test reactions to sodium lauryl sulphate was shown to be small and very consistent, whereas in allergic reactions to nickel sulphate it was generally larger and more variable in size (p less than 0.02). The two major lymphocyte subsets (T4 and T8) were randomly intermixed in both types of reaction and formed the major component of both the perivascular and diffuse dermal infiltrate, without any evidence of selective migration. The T4:T8 ratios were similar in focal and diffuse infiltrates. The number of T6 dendritic (putative Langerhans) cells in the epidermis (per mm inner epidermal length) was usually greatly reduced in irritant reactions (5-16 mm-1, mean 10 mm-1) but remained within normal limits in allergic reactions (6-33 mm-1, mean 21 mm-1) (p less than 0.001). Comparable results were seen with other irritants (mercuric chloride and benzalkonium chloride) and other allergens (neomycin sulphate, ethylene diamine and potassium dichromate). In additional experiments, pairs of biopsies were taken from the reaction and from adjacent unaffected skin. The T6 cell density in the epidermis did not significantly differ between allergic reactions and control skin. By contrast, the irritant reactions had fewer T6 cells than the control skin (p less than 0.001).     

Mast cells in oral erythema multiforme.

We compared the number of mast cells in erythema multiforme lesions, in clinically healthy mucosa between the EM attacks and in healthy mucosa from healthy volunteers. The mast cell count in patients with erythema multiforme was numerically higher than in healthy controls, but the differences were not statistically significant. In erythema multiforme lesions the mast cell count was low in the intensely inflamed superficial lamina propria, but high in normal appearing mucosa between the attacks suggesting local mast cell degranulation in the most intensely inflamed areas.     

Functional and phenotypic analysis of isolated human Langerhans cells and indeterminate cells

In the mixed skin cell lymphocyte culture reaction (MSLR), epidermal cells induce the proliferation in vitro of peripheral blood lymphocytes. Using monoclonal antibodies (MCAB) OKT6 specific for Langerhans cells among epidermal cells and an anti HLA-Dr, we analysed which epidermal cells are necessary in MSLR in man. Inhibition and reduction of the proliferative responses in MSLR conducted respectively with 'anti HLA-Dr and complement' and 'OKT6 and complement'-pretreated epidermal cells suggested that not only Langerhans cells but also other HLA-Dr bearing cells play a major role. Immuno-electron microscopic studies of either HLA-Dr (+) or OKT6 (+) enriched and depleted epidermal cells suspensions: (I) were well correlated with results in MSLR; (2) indicated that Langerhans cells express both T6 and HLA-Dr determinants while indeterminate cells express only the HLA-Dr. No other epidermal cells were found to be either OKT6 or HLA-Dr (+). The data strongly suggest that not only Langerhans cells but also OKT6 (-) HLA-Dr (+) indeterminate cells play a major role in lympho-epidermal interactions.     

Human orf and erythema multiforme

BACKGROUND: Orf is a disease of sheep due to a parapoxvirus. Transmission in man is possible, and is generally benign, self-limited condition. Although, rare complications have been mentioned. We report a case of Orf with erythema multiforme in a young girl. CASE REPORT: A 13-year-old girl presented to our department with an erythema multiform. The cutaneous examination revealed painless erythematous nodule of her right index finger developed 15 days after a contact with a lamb. The diagnosis of Orf complicated by erythema multiforme was made on the basis of her typical history. Lesions heal with symptomatic therapy in 15 days. DISCUSSION: Orf presents in sheeps as a pustular dermatitis or a vesicular oral mucosal lesions, and in man as a single lesion on the site of infection. This lesion generally heals without complications, although secondary infection is not uncommon. Twenty one cases of erythema multiforme have been recorded following infection with the Orf virus. In typical cases, the diagnosis is established by a history of contact with infected animals and the appearance of the lesion. Electron microscopic examination can be helpful sometimes. Lesions regress in 4 to 5 weeks without specific treatment.     

Subcorneal pustules in erythema multiforme

A man aged 24, suffering from Stevens Johnson syndrome precipitated by an upper respiratory infection, developed a skin eruption which consisted of sterile pustules. Histological examination showed subcorneal pustules containing polymorphonuciear leukocytes and no abnormality of the basal part of the epidermis, an appearance indistinguishable from subcorncal pustular dermatosis. The eruption cleared rapidly and did not recur. It is emphasized that the histological appearance of a subcorneal pustule does not necessarily indicate a diagnosis of subcorneat pustular dermatosis (Sneddon & Wilkinson, 1956).     

Subcorneal accumulation of Langerhans cells in erythema gyratum repens

Erythema gyratum repens (EGR) is a cutaneous manifestation of malignant disease. We report an unusual accumulation of activated epidermal Langerhans cells in the upper layer of the epidermis and propose that these cells play an important immunopathological role.     

Isomorphic phenomenon in erythema multiforme

The cutaneous lesions of erythema multiforme have a propensity to localize at previously inflamed or traumatized skin sites. Evidence of the isomorphic phenomenon may be demonstrated in most cases of erythema multiforme by a careful history and physical examination. We present three cases of erythema multiforme which illustrate localization of skin lesions around scratches, recent surgical scars, lacerations, traumatized nail folds and folliculitis. The isomorphic phenomenon may serve as an important clue in understanding the clinical features and possibly, the pathogenesis of erythema multiforme.     

Oral terbinafine and erythema multiforme

Two patients developed classical erythema multiforme while taking oral terbinafine. A case of Stevens-Johnson syndrome occurring after terbinafine therapy has recently been described, but there have been no published reports of an association with erythema multiforme until now.     

Photosensitive erythema multiforme and erythema multiforme-like polymorphous light eruption

BACKGROUND: Photosensitive erythema multiforme (EM) is a rare disorder. It usually occurs only if a herpes virus infection or ingestion of drugs precedes exposure to sunlight in selected patients. METHODS: We report a 37-year-old man who had recurrent EM eruptions following sun exposures over a period of 20 years. Lesions were prevalently located on exposed skin, but unexposed skin and mucosa of the oropharynx were also affected. The patient had poor tolerance to sunlight and denied having herpes simplex infection or using drugs. RESULTS: Provocative phototest induced clinically and histologically similar lesions at low dose thresholds of UVA (10 J/cm2) and UVB (100 mJ/cm2). CONCLUSION: On the basis of clinical and histological findings and results of phototesting, a diagnosis of photosensitive EM was made. The EM-like variant of polymorphous light eruption is discussed in the differential diagnosis.     

皮肤真菌病患者郎格罕细胞和T细胞亚群的检测

应用一组单克隆抗体，ＡＢＣ法对３０例体（股）癣病人外用血及皮损的郎格率细胞和Ｔ细胞亚群进行检测，结果表明病人外周血细胞，皮损中ＨＬＡ－ＤＲ＋细胞均高于正常对照（Ｐ＜０．０５～０．００１），细胞数目无明显改变（Ｐ＞０．０５），细胞在皮肤真菌病中可能递呈真菌抗原给Ｔ细胞。比率无明显改变（Ｐ＞０．０５），说明局部免疫功能基本正常。上述改变说明细胞免疫在皮肤真菌病的发病机理中起着重要作用。     

Histoplasmosis presenting as erythema multiforme and polyarthritis

Erythema multiforme and polyarthritis occurred in association with serologic evidence of primary histoplasmosis. Although such occurrences have been noted in epidemics, recognition of this triad outside of the epidemic setting has been described only once before.