Why is urinalysis done in diagnosing Stevens-Johnson Syndrome (SJS)/Toxic Epidermal Necrolysis (TEN)?

Urinalysis in the Diagnosis of Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN)

Urinalysis is performed in SJS/TEN diagnosis primarily to detect urogenital tract involvement and monitor for complications, as urinary dysfunction is common during the acute phase of the disease.

Role of Urinalysis in SJS/TEN Diagnosis and Management

Detecting Urogenital Involvement

• Urogenital tract involvement is characterized by mucosal erythema, blistering, and erosions 1
• During the acute phase, pain is prominent and urinary dysfunction (dysuria or retention) is common 1
• Urinalysis helps detect:
  • Blood in urine (hematuria) from mucosal erosions
  • Signs of infection (bacteria, white blood cells)
  • Protein in urine (proteinuria) from inflammation

Monitoring for Complications

• Secondary infection by bacteria or candida is a frequent complication of urogenital involvement 1
• Herpes simplex virus (HSV) activation may also occur and can be detected through appropriate testing 1
• Urinalysis helps monitor for:
  • Urinary tract infections
  • Renal complications
  • Systemic complications affecting urinary output

Clinical Significance of Urogenital Involvement

Acute Phase Management

• Catheterization is recommended for all patients to prevent strictures forming in the urethra 1
• Regular examination of the urogenital tract is necessary as part of the initial assessment and throughout the acute illness 1
• Daily documented urogenital review is necessary during the acute illness 1

Long-term Complications

• Erosions of the genital mucosae may persist for many weeks after the acute phase has resolved, ultimately healing with scarring 1
• Serious morbidity can ensue in the form of:
  • Strictures and stenosis of the urethra
  • Phimosis in males
  • Vaginal synechiae in females
  • Resultant urinary and sexual dysfunction 1

Management of Urogenital Involvement

Topical Therapy

• Apply white soft paraffin ointment to the urogenital skin and mucosae immediately and thereafter every 4 hours through the acute illness 1
• Use Mepitel dressings to eroded areas in the vulva and vagina to reduce pain and prevent adhesions 1
• Consider applying a potent topical corticosteroid ointment once daily to the involved, non-eroded, urogenital surfaces 1

Follow-up Considerations

• Patients should be informed about potential long-term urogenital problems during discharge planning 1
• Follow-up with appropriate specialists is necessary to manage potential urogenital complications 2

Common Pitfalls and Caveats

1. Overlooking urogenital involvement: Urogenital examination should be part of the initial assessment and ongoing monitoring in all SJS/TEN patients 1

2. Failure to catheterize: All patients should be catheterized to prevent urethral strictures 1

3. Inadequate monitoring: Daily documented urogenital review is necessary during the acute illness 1

4. Neglecting gender-specific care:

   • In women, early assessment by a vulval specialist is recommended for consideration of dilators to prevent vaginal synechiae 1
   • Uncircumcised male patients should be checked for preputial retractability 1

5. Missing long-term complications: Urogenital problems should be discussed as potential long-term issues during discharge planning 1