Paediatric Erythema Multiforme: Epidemiological, Clinical and Laboratory Characteristics

Erythema multiforme (EM) is an immune-mediated reaction presenting as acrofacial target lesions. Most studies utilize the outdated classification, which includes EM, Stevens-Johnson syndrome and toxic epidermal necrolysis as related entities. We describe here epidemiological, aetiological, clinical, laboratory and treatment characteristics of paediatric EM. This is a retrospective single-centre study, performed between 2000 and 2013. Of 119 children given a diagnosis of EM, only 30 met clinical criteria and were included in this study. Most misdiagnosed cases were non-specific eruptions and urticaria multiforme. Mean age was 11.3 years. Fifty percent had mucosal involvement. An aetiology was observed in half of the patients. Seventy percent of patients were admitted to hospital, 46.7% were treated with systemic steroids. Sixteen percent had recurrent EM. The most common identified infectious agent associated with EM in this study was Mycoplasma pneumonia and the cases associated with this infection may represent the recent entity, mycoplasma-induced rash and mucositis. Association with herpes simplex virus was not observed. Despite being a benign, self-limiting condition, children were over-treated in terms of hospitalization and therapy.

From erythema multiforme to toxic epidermal necrolysis. Same spectrum or different diseases?

Erythema multiforme (EM), Stevens-Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN) are acute bullous disorders associated to different prognosis, mainly due to infections and drugs. More in particular EM in more than 90% is caused by infections (especially Herpes virus infection), while, on the other hand SJS and TEN are referable in more than 95% of cases to drugs. Distinction among these three forms is often controversal and still debated. An attempt to distinguish these forms has been possible mainly according to anamnesis, clinical presentation (morphology, involved sites, extension of lesions) and pathogenetic mechanisms, being on the contrary more difficult from an histopathological point of view. Nowadays a clear diagnosis and a distinction from other life-threatening diseases is possible with the integration of all the mentioned aspects. Moreover, this recognition should be as early as possible in order to perform a prognostic evaluation of the case and to start supportive cares and therapies as soon as possible.

Shape and configuration of skin lesions: targetoid lesions

What is probably the first description of targetoid or iris lesions, as they appear in erythema multiforme (EM), can be found in Thomas Bateman's 1836 textbook "Practical Synopsis of Cutaneous Diseases According to the Arrangement of Dr. Willan." EM was initially described by Bateman and later by von Hebra as an acute self-limiting skin disease, symmetrically distributed on the extremities with typical concentric "targetoid" or "iris" lesions, and often recurrent. Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) were added to this syndrome later. A newer classification has created two disease spectra: EM consisting of EM minor and EM major (or bullous EM), and SJS and TEN. EM minor and EM major are often recurrent, postinfectious (especially after herpes and mycoplasma) disorders with low morbidity and almost no mortality. SJS and TEN are usually severe drug-induced reactions with high morbidity and poor prognosis. The target lesions found in each form of the disease are described and defined. Although the term "target lesion" originated from the description of EM and despite its being the dominant lesion in this disease, it is not pathognomonic for EM, and these lesions can sometimes appear in other diseases. Short descriptions of these other diseases are presented.

Oral mucosal diseases: Erythema multiforme

Erythema multiforme (EM) is a rare acute mucocutaneous condition caused by a hypersensitivity reaction with the appearance of cytotoxic T lymphocytes in the epithelium that induce apoptosis in keratinocytes, which leads to satellite cell necrosis. EM can be triggered by a range of factors, but the best documented association is with preceding infection with herpes simplex virus (HSV). Most other cases are initiated by drugs. EM has been classified into a number of variants, mainly minor and major forms, as it may involve the mouth alone, or present as a skin eruption with or without oral or other lesions of the mucous membrane. EM minor typically affects only one mucosa, and may be associated with symmetrical target skin lesions on the extremities. EM major typically involves two or more mucous membranes with more variable skin involvement. A severe variant of EM major is Stevens-Johnson syndrome, which typically extensively involves the skin. Both EM major and Stevens-Johnson syndrome can involve internal organs and produce systemic symptoms. Treatment of EM is controversial, as there is no reliable evidence. Precipitants should be avoided or treated and, in severe cases, corticosteroids may be needed. Toxic epidermal necrolysis may be similar to Stevens-Johnson syndrome, but many experts regard it as a discrete disease, and therefore it is not discussed here.

Erythema multiforme and related disorders

Erythema multiforme (EM) and related disorders comprise a group of mucocutaneous disorders characterized by variable degrees of mucosal and cutaneous blistering and ulceration that occasionally can give rise to systemic upset and possibly compromise life. The clinical classification of these disorders has often been variable, thus making definitive diagnosis sometimes difficult. Despite being often caused by, or at least associated with, infection or drug therapy, the pathogenic mechanisms of these disorders remain unclear, and as a consequence, there are no evidence-based, reliably effective therapies. The present article reviews aspects of EM and related disorders of relevance to oral medicine clinical practice and highlights the associated potential etiologic agents, pathogenic mechanisms and therapies.

Number IV Erythema multiforme

Erythema multiforme (EM) is an acute mucocutaneous hypersensitivity reaction characterised by a skin eruption, with or without oral or other mucous membrane lesions. Occasionally EM may involve the mouth alone. EM has been classified into a number of different variants based on the degree of mucosal involvement and the nature and distribution of the skin lesions. EM minor typically affects no more than one mucosa, is the most common form and may be associated with symmetrical target lesions on the extremities. EM major is more severe, typically involving two or more mucous membranes with more variable skin involvement - which is used to distinguish it from Stevens-Johnson syndrome (SJS), where there is extensive skin involvement and significant morbidity and a mortality rate of 5-15%. Both EM major and SJS can involve internal organs and typically are associated with systemic symptoms. Toxic epidermal necrolysis (TEN) may be a severe manifestation of EM, but some experts regard it as a discrete disease. EM can be triggered by a number of factors, but the best documented is preceding infection with herpes simplex virus (HSV), the lesions resulting from a cell mediated immune reaction triggered by HSV-DNA. SJS and TEN are usually initiated by drugs, and the tissue damage is mediated by soluble factors including Fas and FasL.

Bupropion-induced erythema multiforme

The high rate of dermatologic adverse effects associated with bupropion use may extend to its sustained-release preparation, currently prescribed extensively for smoking cessation as well as for treatment of depressive conditions. We report what we believe to be the first case, in a 31-year-old woman, of erythema multiforme after administration of sustained-release bupropion (Wellbutrin SR) for treatment of depression. This report emphasizes that prescribers must aggressively follow up their patients who have rashes or urticaria, discontinuing the medication as soon as erythema multiforme is suspected and watching closely for the emergence of potentially life-threatening dermatologic conditions.

Stevens-Johnson syndrome and toxic epidermal necrolysis are severity variants of the same disease which differs from erythema multiforme

A new classification, based on the pattern and distribution of cutaneous lesions, separates erythema multiforme major from Stevens-Johnson syndrome. A retrospective re-classification of 76 cases supported the validity of that separation by demonstrating differing causes and pathology. Another prospective international case-control study found differing demographic characteristics and risk factors between erythema multiforme major on the one hand and Stevens-Johnson syndrome or toxic epidermal necrolysis on the other. Erythema multiforme major was mainly related to Herpes virus infection, while Stevens-Johnson syndrome and toxic epidermal necrolysis were associated with drug reactions.

Autoantibodies against desmoplakin I and II define a subset of patients with erythema multiforme major

In a previous report, we described autoantibodies against the desmosomal plaque proteins desmoplakin I and II (dp I and II) in patients with erythema multiforme (EM) major. In the present study we investigated ten EM major and eight EM minor patients for circulating autoantibodies and performed clinical and immunomorphological evaluations. Seven out of ten EM major patients revealed anti-dp I and II autoantibodies. Antigens were biochemically characterized by Western blotting and immunoprecipitation of epithelial-cell-derived protein extracts. These autoantibodies bind in vivo to lesional skin/mucosa in a pemphigus-type dotted pattern along the cytoplasmic membranes of keratinocytes. Ultrastructural immunolocalization studies confine in vivo bound autoantibodies to the cytoplasmic desmosomal plaque. Autoantibody binding studies with the sera of such patients demonstrate that the target antigens are not restricted to squamous epithelia but are also expressed in simple and transitional epithelia, on hepatocytes, and on cells of mesenchymal origin, e.g., myocardial cells. Comparing the clinicopathological features of ten patients with EM major, we could not define any discriminating clinical symptoms among patients with or without autoantibodies. Histopathological examination, however, revealed that only patients with EM major and autoantibodies against dp I and II show suprabasal acantholysis in lesional skin and mucous membranes, suggesting a potential role of the humoral immune response in the pathogenesis of this disease. These findings suggest that these autoantibodies define a subset of patients within the clinical spectrum of EM.

Erythema multiforme with mucous membrane involvement and Stevens-Johnson syndrome are clinically different disorders with distinct causes

BACKGROUND AND DESIGN

It was recently suggested that erythema multiforme (EM) majus and Stevens-Johnson syndrome (SJS) could be separated as two distinct clinical disorders with similar mucosal erosions but different patterns of cutaneous lesions. To test that hypothesis, we made a single-center retrospective study of severe EM with skin and mucosal involvement. Based on a review of clinical photographs, the skin lesions were reclassified as EM when these lesions were made of typical or raised atypical targets that were located on the extremities and/or the face, or as SJS when these lesions were made of flat atypical targets or purpuric maculae that were widespread or distributed on the trunk. Another investigator who was blinded for that clinical classification related each case to its more probable cause (eg, herpes infection or drug-induced reaction), by using scores derived from the medical charts.

RESULTS

The majority (80%) of 76 cases could be classified as one of the two disorders: 28 as EM (37%), 33 as SJS (43%), and 15 as "undetermined" (20%). By using causal scores, the 76 cases were classified as herpes-induced (n = 18 [24%]), drug-induced (n = 40 [52%]), and "other" (n = 18 [24%]). There was a strong correlation between the clinical classification and the probable cause (K = 0.87, P < .001). Specifically, EM was mostly related to herpes (17 of 28 cases) or to other causes (eight of 28 cases); however, EM was rarely related to drugs (three of 28 cases), while SJS was nearly always related to drugs (28 of 33 cases) and never to herpes.

CONCLUSIONS

The results of this study support the suggestion that EM with mucosal lesions and SJS could be distinguished on the basis of two different clinical patterns. In addition, a strong relationship was observed between each pattern and specific causes. This is one more piece of evidence that suggests that EM with mucosal lesions and SJS are actually two different diseases.

The spectrum of Stevens-Johnson syndrome and toxic epidermal necrolysis: a clinical classification

The nosology of severe bullous erythema multiforme (EM), Stevens-Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN) remains controversial. To conduct a prospective case-control study of the etiologic factors of these diseases, we needed to define criteria for classifying the cases. After having reviewed photographs of the skin lesions of more than 200 patients, an international group of dermatologists proposed a classification based on the pattern of "EM-like lesions" (categorized as typical targets, raised or flat atypical targets, and purpuric macules) and on the extent of epidermal detachment. The "consensus" classification in five categories was as follows: bullous erythema multiforme, detachment below 10% of the body surface area (BSA) plus localized typical targets or raised atypical targets; SJS, detachment below 10% of the BSA plus widespread erythematous or purpuric macules or flat atypical targets; overlap SJSTEN, detachment between 10% and 30% of the BSA plus widespread purpuric macules or flat atypical targets; TEN with spots, detachment above 30% of the BSA plus wide-spread purpuric macules or flat atypical targets; TEN without spots, detachment above 10% of the BSA with large epidermal sheets and without any purpuric macules or target. Whether all five categories proposed represent distinct etiopathologic entities will require further epidemiologic and laboratory investigations.

Clinical classification of cases of toxic epidermal necrolysis, Stevens-Johnson syndrome, and erythema multiforme

BACKGROUND AND DESIGN

To conduct a prospective case-control study about causative factors of severe bullous erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis, we needed to define criteria for classifying the cases and standardize the collection of data so that cases could be reliably diagnosed according to this classification. Based on review of case histories and photographs of patients, a group of experts proposed a classification based on the pattern of erythema multiforme-like lesions (categorized as typical targets, raised or flat atypical targets, and purpuric macules) and on the extent of epidermal detachment. An atlas illustrating this classification that included photographs and schematic drawings was developed. We compared the evaluations of 28 cases by four nonphysicians relying on the atlas with the evaluations of the same cases by five experts not using the atlas to determine the usefulness of this atlas for classifying cases according to our nosologic schema.

RESULTS

The following consensus classification in five categories was proposed: bullous erythema multiforme, detachment below 10% of the body surface area plus localized "typical targets" or "raised atypical targets"; Stevens-Johnson syndrome, detachment below 10% of the body surface area plus widespread erythematous or purpuric macules or flat atypical targets; overlap Stevens-Johnson syndrome-toxic epidermal necrolysis, detachment between 10% and 30% of the body surface area plus widespread purpuric macules or flat atypical targets; toxic epidermal necrolysis with spots, detachment above 30% of the body surface area plus widespread purpuric macules or flat atypical targets; and toxic epidermal necrolysis without spots, detachment above 10% of the body surface area with large epidermal sheets and without any purpuric macule or target. Using the atlas, the nonexperts showed excellent agreement with the experts.

CONCLUSION

This study suggests that an illustrated atlas is a useful tool for standardizing the diagnosis of acute severe bullous disorders that are attributed to drugs or infectious agents. Whether the five categories proposed represent distinct etiopathologic entities will require further epidemiologic and laboratory investigations.

Erythema multiforme in children: unusual clinical features with seasonal occurrence

Eighty-six cases of erythema multiforme (EM) were studied based on the distribution of skin lesions. Twenty-nine patients had distinct facial skin lesions as well as lesions on the extremities (Group A) and 57 patients had skin lesions only on the extremities (Group B). Patients in Group A were younger than those in Group B; the average ages being 7.5 and 25.2 years, respectively. In Group A, the disease occurred mainly in winter, while, in Group B, it began most frequently in summer. Preceding ulcerated pernio was seen in 11 patients of Group A, but only one of Group B. Histopathologically, both groups are compatible with a diagnosis of EM, although the seasonal occurrence of facial involvement in Group A may suggest a specific etiological relationship to cold.