[Pemphigoid gestationis without blisters]

Diffusive mediator feedbacks control the health-to-disease transition of skin inflammation

The spatiotemporal dynamics of inflammation provide vital insights into the understanding of skin inflammation. Skin inflammation primarily depends on the regulatory feedback between pro- and anti-inflammatory mediators. Healthy skin exhibits fading erythema. In contrast, diseased skin exhibits expanding erythema with diverse patterns, which are clinically classified into five types: circular, annular, arcuate, gyrate, and polycyclic. Inflammatory diseases with expanding erythema are speculated to result from the overproduction of pro-inflammatory mediators. However, the mechanism by which feedback selectively drives the transition from a healthy fading erythema to each of the five types of diseased expanding erythema remains unclear. This study theoretically elucidates the imbalanced production between pro- and anti-inflammatory mediators and prospective treatment strategies for each expanding pattern. Our literature survey showed that eleven diseases exhibit some of the five expanding erythema, thereby suggesting a common spatiotemporal regulation underlying different patterns and diseases. Accordingly, a reaction-diffusion model incorporating mediator feedback reproduced the five observed types of diseased expanding and healthy fading patterns. Importantly, the fading pattern transitioned to the arcuate, gyrate, and polycyclic patterns when the productions of anti-inflammatory and pro-inflammatory mediators were lower and higher, respectively than in the healthy condition. Further depletion of anti-inflammatory mediators caused a circular pattern, whereas further overproduction of pro-inflammatory mediators caused an annular pattern. Mechanistically, the bistability due to stabilization of the diseased state exhibits circular and annular patterns, whereas the excitability exhibits the gyrate, polycyclic, arcuate, and fading patterns as the threshold of pro-inflammatory mediator concentration relative to the healthy state increases. These dynamic regulations of diffusive mediator feedback provide effective treatment strategies for mediator production wherein skins recover from each expanding pattern toward a fading pattern. Thus, these strategies can estimate disease severity and risk based on erythema patterns, paving the way for developing noninvasive and personalized treatments for inflammatory skin diseases.

Nonbullous pemphigoid: A systematic review

BACKGROUND

Bullous pemphigoid is an autoimmune disease that typically presents with tense bullae and severe pruritus. However, bullae can be lacking, a subtype termed nonbullous pemphigoid.

OBJECTIVE

To summarize the reported characteristics of nonbullous pemphigoid.

METHODS

The EMBASE and MEDLINE databases were searched using "nonbullous pemphigoid" and various synonyms. Case reports and series describing nonbullous pemphigoid were included.

RESULTS

The search identified 133 articles. After selection, 39 articles were included, presenting 132 cases. Erythematous, urticarial plaques (52.3%) and papules/nodules (20.5%) were the most reported clinical features. The mean age at presentation was 74.9 years. Histopathology was commonly nonspecific. Linear depositions of IgG and/or C3 along the basement membrane zone were found by direct immunofluorescence microscopy in 93.2%. Indirect immunofluorescence on salt-split skin was positive in 90.2%. The mean diagnostic delay was 22.6 months. A minority of patients (9.8%) developed bullae during the reported follow-up.

LIMITATIONS

Results are mainly based on case reports and small case series.

CONCLUSION

Nonbullous pemphigoid is an underdiagnosed variant of pemphigoid that most often does not evolve to bullous lesions and mimics other pruritic skin diseases. Greater awareness among physicians is needed to avoid delay in diagnosis.

Polymorphic eruption of pregnancy presented with targetoid lesions: a report of two cases

Background

Skin lesions in pregnant women could be caused by physiologic or pathologic changes. Polymorphic eruption of pregnancy (PEP), which manifests as various types of skin lesions, is the most common pregnancy dermatosis. Thus, PEP could mimic other skin diseases related to unfavorable maternal and fetal outcomes.

Main Observations

Two PEP patients with targetoid lesions are presented here. One of them was a primigravida, whereas the other was a secundigravida. Both patients had singleton pregnancies and skin rash which started during the third trimester. The lesions began on the abdomen and then spread to the trunk and extremities. The face, palms, soles, and mucosa were not affected. Pruritus was observed but no other systemic symptoms were reported. Both patients delivered healthy, term infants without complications.

Conclusion

Targetoid lesions in PEP are an uncommon presentation, and the differential diagnosis of PEP along with other dermatoses should be considered. However, the prognosis for this type of PEP is not different from that for classic PEP.

Glucocorticosteroid-resistant pemphigoid gestationis: successful treatment with adjuvant immunoadsorption

A 40-year old prima para presented with multiple urticaria-like plaques and severe pruritus 2 weeks prior to giving birth by cesarean section. Three days after birth, the disease flared up and tense blisters appeared on hands, lower arms and feet. Based on the clinical presentation, direct immunofluorescence microscopy, complement binding test and detection of high levels of circulating anti-BP180 antibodies, the diagnosis of pemphigoid gestationis was established. Despite treatment with class IV topical corticosteroid and prednisolone p.o. up to 60 mg/day, both skin lesions and severe pruritus progressed accompanied by increasing anti-BP180 antibody serum levels. In order to continue breast feeding, the prednisolone dose could not be further increased and 10 immunoadsorptions over 4 weeks were performed. During this period, skin lesions cleared rapidly, pruritus subsided and BP180-specific serum autoantibodies decreased by 99.5% allowing the reduction of prednisolone to 7.5 mg/day. We conclude that immunoadsorption is an effective and safe adjuvant therapeutic option for severe pemphigoid gestationis.

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.

[Relevance of histological examination in the diagnosis of autoimmune bullous dermatoses]

The histopathological picture of many autoimmune bullous dermatoses is considered to be relatively characteristic. However, different entities may show similar histological findings. In addition, the picture depends on both the stage of the disease and prior treatment. Autoimmune bullous dermatoses are characterized by the production of autoantibodies to structural proteins of the skin. In most instances, the autoantigens have been identified and are available as recombinant proteins. Utilizing these recombinant forms, specific and sensitive assays have been developed for the detection of circulating autoantibodies in the serum. The detection of autoantibodies in skin or mucous membranes and/or serum is required for the diagnosis of autoimmune bullous dermatoses. The task of the dermatopathologist in the diagnostic process of autoimmune bullous dermatoses is to describe precisely the histopathological findings, to mention differential diagnoses and to recommend how these can be confirmed or excluded by immunopathological and immunoserological studies.

[Mucous membrane pemphigoid: IgG and IgA antibodies against the BP180 antigen]

INTRODUCTION

Mucous membrane pemphigoid is a group of autoimmune bullous diseases, mediated by autoantibodies directed against different proteins in the dermoepidermal junction, including the BP180 antigen.

PATIENTS, MATERIAL AND METHODS

We included five patients with MMP in this study. We studied the presence of circulating autoantibodies against the BP180 antigen and against recombinant extracellular fragments of this protein.

RESULTS

We detected the presence of circulating antibodies against BP180 in all of the patients. Indirect immunofluorescence (IIF) studies were positive in 2 patients (20 %), as well as in 2 patients via salt-split studies. We found reactivity to the extracellular fragment of BP180 (LAD-1) in 3 patients, 2 of them via IgA and 1 with IgG. The serum of only 2 patients recognized the NC16A fragment, and 4 of the 5 patients had antibodies against the carboxy-terminal domain BP180 4575.

CONCLUSIONS

Molecular biology techniques are very important to complement the diagnosis of MMP, especially when the results of hematoxylin-eosin or IF studies are not satisfactory for a diagnosis of MMP.