Pemphigus Vulgaris: Impact on Adults and Children
Pemphigus vulgaris (PV) is a rare autoimmune blistering disease that predominantly affects adults aged 40-60 years, but can occur in children (representing 1-4% of cases), with children generally experiencing a more favorable prognosis and better treatment response than adults. 1, 2
Disease Characteristics in Adults
Clinical Presentation and Severity
- Adults typically present between the third and sixth decades of life, with oral mucosa being the first site of involvement in the majority of cases 1, 3
- The disease may remain confined to mucosal surfaces or extend to skin after an average lag period of 4 months 1
- Mucocutaneous PV in adults carries significantly higher mortality (34-42%) compared to predominantly mucosal disease (1-17%) 1, 3
- Diagnostic delay averages 6 months from symptom onset, particularly longer in men 4
Disease Course in Adults
- 76% of adult patients experience recalcitrant disease requiring prolonged immunosuppression 4
- Complete remission rates in adults are 38% at 3 years, 50% at 5 years, and 75% at 10 years from diagnosis 1
- Adverse effects from immunosuppressive therapy occur in 78% of adult patients 4
- Mortality in adults is approximately 10%, with septicemia being the main cause of death 5
Disease Characteristics in Children
Epidemiology and Prognosis
- Children with PV have a generally favorable course with better prognosis compared to adult PV 1
- Childhood cases can be subdivided into childhood PV (age <12 years) and juvenile PV (age 12-18 years), which helps delineate potential adverse effects of medications 1
- The ratio of childhood cases ranges from 1-4% of all PV cases, though one series reported 2.9% 2, 6
Clinical Course in Children
- Despite better overall prognosis, pediatric PV shows a relapsing course similar to adults, with all followed cases showing at least one relapse over 2-4 years 6
- Severe cases resistant to conventional therapies can occur in children, requiring advanced treatments 2
- A self-limiting form of PV can occur in neonates born to mothers with PV due to transplacental transfer of autoantibodies 1
Treatment Differences Between Adults and Children
Pediatric Treatment Approach
- Treatment after initial systemic corticosteroids is similar to adult regimens, with the same adjuvant therapies available 1
- Due to rarity, there are no randomized controlled trials for systemic agents in pediatric PV 1
- Rituximab has been used successfully in childhood pemphigus, though careful consideration of risks is required 1, 2
- If pregnancy is exposed to rituximab, the baby should avoid live vaccines for at least the first 6 months of life 1
Adult Treatment Considerations
- Systemic corticosteroids remain first-line therapy, with 87% of adults requiring corticosteroids often combined with adjunctive immunosuppressives, particularly azathioprine 4
- Pain management teams may be needed for painful skin or mucosal lesions, and dietician input if oral intake is impaired 1
- Only 18% of adult patients achieve disease resolution within 3 months 4
Key Clinical Pitfalls
Diagnostic Challenges
- PV should not be neglected in the differential diagnosis of bullous lesions in childhood despite its rarity 6
- Diagnostic delay is common when PV is confined to oral mucosa, and the disease may be misdiagnosed as other oral conditions 3
- Men present later than women, contributing to longer diagnostic delays 4
Neonatal Considerations
- Approximately 30-45% of neonates born to mothers with PV may have transient pemphigus lesions at birth, which resolve within 4 weeks spontaneously or with mild topical corticosteroids 7, 8
- Pemphigus vulgaris in pregnancy can result in fetal growth retardation, intrauterine death, and premature delivery 8
- Transplacental crossing of desmoglein 1 antibodies in pemphigus foliaceus rarely leads to neonatal skin lesions, unlike desmoglein 3 antibodies in PV 8