Bullous Diseases in Children: A Review of Clinical Features and Treatment Options

Diagnosis, treatment, and long-term outcomes of pediatric pemphigus: a retrospective study at tertiary medical centers

BACKGROUND

Pediatric pemphigus is a rare bullous disease that represents a diagnostic and therapeutic challenge;  evidence on patients' response to various treatments and long-term surveillance data are lacking. We aimed to investigate pediatric pemphigus patients' characteristics, diagnosis, therapeutics, response, and long-term follow-up.

METHODS

This is a retrospective study of all pemphigus patients aged <18 years, diagnosed between 2000 and 2023, from three tertiary medical centers in Israel. The diagnosis was confirmed by positive immunofluorescence.

RESULTS

Twelve pediatric pemphigus patients were included (mean age 10.7 ± 4.3 years, male:female ratio 1:1). Mean diagnostic delay was 11.1 ± 12.6 months (range 1.8-36 months). Most patients had pemphigus vulgaris with mucosal involvement (58.3%). First-line treatment for all patients included systemic corticosteroids (sCS), with a treatment duration (including tapering down) of 28 ± 18.4 months. Hospitalization did not yield better outcomes. Only three patients achieved sustained complete response with sCS treatment (25.0%), and the rest required additional therapeutics, most commonly rituximab. Rituximab showed a good safety profile and therapeutic response. Follow-up was recorded up to 18.1 years after diagnosis (mean: 5.6 years). Three of five patients with information available more than 5 years after the pemphigus diagnosis still exhibited disease symptoms.

CONCLUSIONS

Pediatric pemphigus is associated with a significant diagnostic delay. While sCS can induce remission in most patients as a first-line treatment, long-term disease control requires additional immunomodulators. Long-term follow-up reveals a chronic yet mostly benign disease course in this population and advocates for the use of rituximab in pediatric pemphigus patients.

Treatment of Pediatric Pemphigus Foliaceus

Pemphigus foliaceus (PF) is an autoimmune blistering disease limited to the superficial skin without mucosal involvement. It is clinically, histologically, and immunopathologically distinct from pemphigus vulgaris (PV). As data on pediatric PF is often merged with data on both pediatric and adult PV patients, isolating clinical outcomes in pediatric PF is not always possible. Therefore, the authors of this review analyzed clinical outcomes following therapy in pediatric PF patients only. A search of databases resulted in 33 pediatric patients with PF. In total, 19 (57.6%) patients were treated with conventional immunosuppressive therapies (CISTs), which consisted of systemic corticosteroids and multiple immunosuppressive agents (ISAs). Further, 14 (42.4%) patients were treated with biologic agents, predominantly rituximab (RTX). The mean age of those treated with biologics was 12.8 years (range = 0.88-18 years) compared to 8.9 years (range = 0.92-15 years) of those treated with CIST (p = 0.01). Treatment with biologics was initiated significantly longer after the diagnosis of PF when compared to patients treated with CIST (p = 0.003). RTX was used in all patients who received biologic therapy. Two (6%) patients also received intravenous immunoglobulin. When clinical outcomes were compared between CIST and biologic therapy, rates of clinical remission, partial remission, and relapse, were not statistically significantly different between groups. When RTX was used, rates of relapse and adverse events were higher in those treated with the lymphoma protocol (375 mg/m2 once weekly for four weeks) compared to those treated with the rheumatoid arthritis protocol (two doses of 1,000 mg two weeks apart) (p < 0.0001). The incidence of adverse events was statistically significantly higher in patients treated with CIST when compared to RTX (p = 0.003). These included both physical and psychological changes. The infection rate after treatment with RTX was 7.1%. These outcomes occurred during a follow-up of 12.5 months (range = 1-36 months) in the CIST group and 20.5 months (range = 6-67 months) in the biologic therapy group. The difference in the follow-up period was not statistically significant. The literature suggests that biologics are superior to CIST in treating pemphigus patients. The results of this review suggest similar responses to therapy in pediatric PF patients treated with biologics compared to CIST. This may have been due to a limited duration of follow-up and a lack of detailed treatment outcomes in pediatric PF patients. The data in this review strongly suggests that specific treatment protocols need to be developed and implemented for pediatric PF patients. These patients are at a critical phase in life where PF therapy can influence or affect physical growth, hormonal changes, psychosocial development, and essential education.

Novel PGM3 mutation in two siblings with combined immunodeficiency and childhood bullous pemphigoid: a case report and review of the literature

BACKGROUND

Bullous pemphigoid is the most common autoimmune subepidermal blistering disorder with a low incidence in childhood. Combined immunodeficiencies (CIDs) are a group of monogenic inborn errors of immunity (IEIs) characterized by T- and B-cell dysfunction leading to recurrent infections, lymphoproliferation, predisposition to malignancy, and autoimmunity. Here, we report two Afghan siblings with a diagnosis of CID and extremely rare manifestation of diffuse bullous pemphigoid skin lesions.

CASE PRESENTATION

The older sibling (patient 1) was a 32-month-old male with facial dysmorphism, protracted diarrhea, failure to thrive, recurrent oral candidiasis, recurrent otitis media with tympanic membrane perforation, who had been previously diagnosed with CID. While he was under treatment with intravenous immunoglobulin (IVIg), he developed extensive blistering lesions, which were diagnosed as childhood bullous pemphigoid. Methylprednisolone and azathioprine were added to the regimen, which resulted in a remarkable improvement of the skin lesions and also the feeding condition. However,2 weeks later, he was re-admitted to the intensive care unit (ICU) and eventually died due to fulminant sepsis. Later, his 12-month-old sister (patient 2) with similar facial dysmorphism and a history of developmental delay, food allergy, recurrent oral candidiasis, and respiratory tract infections also developed blistering skin lesions. She was under treatment for occasional eczematous lesions, and had been receiving IVIg for 3 months due to low levels of immunoglobulins. Further immunologic workup showed an underlying CID and thus treatment with IVIg continued, gradually improving her clinical condition. The genetic study of both siblings revealed a novel homozygous mutation in exon 7 of the PGM3 gene, c.845 T > C (p.Val282Ala).

CONCLUSIONS

Dermatologic disorders may be the presenting sign in patients with CID and mutated PGM3. This case report further extends the spectrum of skin manifestations that could be observed in PGM3 deficiency and emphasizes the importance of considering CIDs during the assessment of skin disorders, particularly if they are extensive, recurrent, refractory to treatment, and/or associated with other signs of IEIs.

Acral blisters in neonates: Three rare and benign diseases

Exclusive acral involvement in neonatal pemphigus is unusual. Blisters in neonatal bullous pemphigoid, affecting 2%-3% of newborns of mothers with gestational pemphigoid, can be located in the trunk, limbs and acral areas. Unlike neonatal bullous pemphigoid, which can appear up to 5 days after birth, neonatal pemphigus is often revealed at birth. They are benign diseases in newborns. There is no correlation between the disease severity in babies and mothers. Neonatal risk is dominated by the side effects of corticosteroid therapy.

Linear Immunoglobulin a Bullous Dermatosis in Children

Linear Immunoglobulin A Bullous Disease (LABD) is a rare dermatosis whose pathomechanisms are not yet completely understood. LABD has different features characterizing adults and children in terms of potential triggers, clinical manifestations, and prognosis. The aim of the present study is to review all neonatal and pediatric cases of LABD and summarize the major characteristics. Childhood LABD is mainly idiopathic with a benign prognosis. Neonatal cases are difficult to differentiate from infectious diseases and usually have a poor prognosis. Drugs are one of the possible triggers that can activate autoimmune responses through antigen mimicry and epitope spreading as well as different stimuli (e.g., infections, inflammatory diseases, trauma). The gold standard for the diagnosis is based on direct immunofluorescence. Prognosis is generally favorable but often depends on the prompt dermatological diagnosis, treatment and follow-up guaranteed by a multidisciplinary team, including pediatricians for this group of age.

Epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita is a rare autoimmune disease, characterized by the synthesis of anti-collagen VII autoantibodies, the main component of hemidesmosome anchoring fibrils. The antigen-antibody binding elicits a complex inflammatory response, which culminates in the loss of dermo-epidermal adhesion of the skin and/or mucous membranes. Skin fragility with bullae, erosions, and milia in areas of trauma characterizes the mechanobullous form of the disease. In the inflammatory form of epidermolysis bullosa acquisita, urticarial inflammatory plaques with tense bullae, similar to bullous pemphigoid, or mucosal lesions can determine permanent scars and loss of functionality in the ocular, oral, esophageal, and urogenital regions. Due to the similarity of the clinical findings of epidermolysis bullosa acquisita with other diseases of the pemphigoid group and with porphyria cutanea tarda, the diagnosis is currently confirmed mainly based on the clinical correlation with histopathological findings (pauci-inflammatory subepidermal cleavage or with a neutrophilic infiltrate) and the demonstration of the presence of anti-collagen VII IgG in situ by direct immunofluorescence, or circulating anti-collagen VII IgG through indirect immunofluorescence and/or ELISA. There is no specific therapy for epidermolysis bullosa acquisita and the response to treatment is variable, usually with complete remission in children and a worse prognosis in adults with mucosal involvement. Systemic corticosteroids and immunomodulators (colchicine and dapsone) are alternatives for the treatment of mild forms of the disease, while severe forms require the use of corticosteroid therapy associated with immunosuppressants, intravenous immunoglobulin, and rituximab.

Bronchiolitis Obliterans With Anti-Epiplakin Antibodies in a Boy With Paraneoplastic Pemphigus

Paraneoplastic pemphigus is a rare and severe autoimmune blistering disease characterized by a recalcitrant and severe mucositis, and polymorphic cutaneous lesions, associated with benign and malignant neoplasms. Paraneoplastic pemphigus is caused by production of autoantibodies against various epidermal proteins involved in cell adhesion. Bronchiolitis obliterans (BO) is one of the leading causes of mortality in these patients. Recent advances have associated the presence of anti-epiplakin antibodies with the development of BO in adult patients. Here we describe the first pediatric patient in whom the association of anti-epiplakin antibodies and BO have been reported so far.

Skin Manifestations and Coeliac Disease in Paediatric Population

Celiac disease (CD) is an immune-mediated enteropathy caused by gluten ingestion, affecting approximately 1% of the worldwide population. Extraintestinal symptoms may be present as the first signs of CD, years before the CD diagnosis is made. A great variety of extraintestinal manifestations may be associated with CD. Cutaneous manifestations represent the main extraintestinal manifestations, with dermatitis herpetiformis being the most common in patients with CD. In adults, it has been demonstrated that the role of a gluten-free diet is crucial not only for the recovery of signs and symptoms associated with CD but also for cutaneous manifestations, which often improve after gluten avoidance. In children with CD, the association with skin disorders is well documented regarding dermatitis herpetiformis, but studies considering other dermatological conditions, such as psoriasis and atopic dermatitis, are few. The prevalence and manifestations of dermatological disorders in celiac children are often different from those in adults, explaining the gap between these populations. In addition, the therapeutic role of a gluten-free diet in the improvement in skin alterations is not fully understood in children and in adult population except for dermatitis herpetiformis. Therefore, cutaneous CD symptoms need to be known and recognized by physicians despite their specialties to improve early CD diagnosis, which is critical for a better prognosis. This review describes the current scientific evidence on skin manifestations associated with CD in the pediatric population.

Pediatric epidermolysis bullosa acquisita: A review

Epidermolysis bullosa acquisita (EBA) is an acquired autoimmune blistering skin disorder that is rare in adults and even rarer in childhood. This review aims to identify cases of pediatric EBA and report their clinical features and course. Our literature review was conducted in MEDLINE^® using the search terms related to juvenile epidermolysis bullosa acquisita. We identified 40 cases of pediatric EBA. Mucosal tissues were affected in 29 out of 40 cases. Treatment mostly consisted of a systemic corticosteroid combined with dapsone. Prognosis is favorable with 17 of 40 cases achieving complete remission, 9 of 40 with complete control with therapy, 12 of 40 with partial control with therapy, 1 of 40 with no response to therapy, and 1 of 40 terminating treatment early. Though it is a rare condition, childhood EBA should still be included in the differential diagnosis of pediatric blistering diseases.

Risk Factors for Mucosal Involvement in Bullous Pemphigoid and the Possible Mechanism: A Review

Bullous pemphigoid (BP) is the most common type of autoimmune bullous disease and is characterized by the presence of circulating anti-BP180 and/or anti-BP230 autoantibodies. Patients with BP often present with tense blisters and erythema, mainly on the trunk and limbs, but a few patients also have mucosal involvement. In this article, we discuss the fact that BP patients with mucosal involvement tend to have more serious conditions and their disease is more difficult to control. Potential risk factors for mucous involvement include earlier age at onset, drugs such as dipeptidyl peptidase-4 inhibitors, cancer, and blood/serum biomarkers, including lower eosinophil count, higher erythrocyte sedimentation rate, IgG autoantibodies against both the NH₂- and COOH-termini of BP180, and the absence of anti-BP230 antibodies. IgA and C3 deposition at the dermo-epidermal junction may also be present. Understanding these risk factors may benefit earlier diagnosis of these patients and promote the development of novel treatments. What's more, it's helpful in deeper understanding of BP development and the relationship between BP and mucous membrane pemphigoid (MMP).