What are the secondary causes of enuresis in adolescents and how should they be assessed?

Secondary Causes of Enuresis

Secondary enuresis in adolescents is most commonly triggered by psychological stressors (parental divorce, school trauma, sexual abuse, hospitalization), medication side effects (lithium, valproic acid, clozapine, theophylline), urinary tract infections, constipation, sleep apnea, and rarely, serious underlying conditions like diabetes insipidus from intracranial tumors 1.

Key Distinction: Secondary vs Primary

Secondary enuresis occurs in previously dry children (at least 6 months of continence) who begin bedwetting again. This represents approximately 26% of adolescent enuresis cases 2. The return of bedwetting after a dry period is a red flag that demands investigation for underlying causes 1.

Major Secondary Causes by Category

Psychosocial Stressors (Most Common in Secondary Enuresis)

Secondary enuresis frequently represents a regressive symptom response to trauma or stress 1. Specifically assess for:

• Parental divorce or family disruption
• School trauma or bullying
• Sexual abuse (must be specifically explored with sensitivity) 1
• Hospitalization or medical procedures
• Out-of-home placement
• Recent death of a parent 3

These children typically have secondary enuresis rather than primary, and the timing of symptom onset correlates with the stressor 1.

Medication-Induced Enuresis

Certain medications cause secondary enuresis as a side effect, though this is relatively uncommon 1:

• Lithium
• Valproic acid
• Clozapine
• Theophylline

Always obtain a complete medication history 1.

Medical Conditions Requiring Urgent Evaluation

Urinary Tract Infections

• More common in females (all 13 patients with UTI history in one adolescent study were female) 2
• Requires urinalysis and culture in all cases 1
• Dysuria, frequency, and urgency should be specifically explored 1

Constipation/Fecal Impaction

• Significantly more common in primary enuresis (74.59% vs 57.54%) but still prevalent in secondary 4
• Mechanical pressure on bladder from stool impaction
• Palpate abdomen for fecal masses 1
• Treatment of constipation often eliminates enuresis 1

Sleep-Disordered Breathing/Sleep Apnea

• Assess for snoring, enlarged tonsils/adenoids, upper airway obstruction 1
• Check nasal patency and voice quality 1
• Surgical correction of upper airway obstruction can cure enuresis 1

Diabetes Insipidus (Rare but Critical)

• Consider in adolescents with secondary enuresis plus growth delay, late puberty, or morning hypernatremia 5
• Can be early manifestation of intracranial germinomatous germ cell tumors, particularly in male adolescents 5
• Water deprivation test confirms diagnosis 5
• Requires urgent brain MRI if suspected 5

Comorbid Conditions

• Attention deficit hyperactivity disorder (ADHD) - decreases treatment success 6, 7
• Eating disorders (anorexia, polyphagia) - reported in 6% of adolescent enuretics 2
• Psychiatric disorders - present in 20-30% of children with nocturnal enuresis 8

Assessment Algorithm for Secondary Enuresis

History (Most Critical Component)

The history is more valuable than expensive testing 6. Specifically document:

1. Timing and pattern: When did dry period end? Correlation with life events?
2. Daytime symptoms: Urgency, holding maneuvers, interrupted micturition, weak stream, daytime incontinence 6
3. Voiding frequency: Obtain 2-week frequency-volume chart 1
4. Stressor assessment: Recent trauma, family changes, abuse history 1
5. Medication review: All current medications 1
6. UTI history: Previous infections, dysuria 6
7. Bowel habits: Constipation, encopresis 1
8. Sleep symptoms: Snoring, witnessed apnea 1
9. Growth/development: Delays, late puberty 5
10. Family history: Enuresis in parents 1

Physical Examination (Mandatory)

Never start treatment without examination 1:

• Nasal/pharynx: Enlarged adenoids, tonsils 1
• Abdomen: Bladder distention, fecal impaction 1
• Genitalia: Meatal abnormalities, epispadias, phimosis 1
• Back: Sacral dimple, spinal anomalies 1
• Neurologic: Complete exam for subtle dysfunction 1

Laboratory/Imaging

• Urinalysis and culture: Mandatory in all cases 1
• Further imaging: Only if history/exam suggests congenital malformations, neurologic disorders, or refractory to initial therapy 9, 10
• Brain MRI: If diabetes insipidus suspected (growth delay, late puberty, polyuria) 5

Critical Red Flags Requiring Specialist Referral

Immediate urologic referral indicated for 6, 1:

• Weak urinary stream requiring abdominal pressure
• Continuous daytime incontinence
• Abnormal genital anatomy
• Suspected spinal cord anomaly
• Recurrent UTIs

Endocrine evaluation for:

• Growth delay + secondary enuresis + polyuria (rule out diabetes insipidus/intracranial tumor) 5

Common Pitfalls

1. Assuming all secondary enuresis is psychological: While stress is common, always rule out medical causes first 1
2. Missing sexual abuse: Requires specific, sensitive questioning in private interview 1
3. Overlooking constipation: Present in majority of cases and mechanically contributes to symptoms 4
4. Ignoring medication history: Drug-induced enuresis is easily reversible if identified 1
5. Dismissing rare but serious causes: Diabetes insipidus from intracranial tumors presents with secondary enuresis 5

Treatment Approach

Address the underlying cause first 1:

• Psychological stressors: Individual psychotherapy, crisis intervention, family therapy 1
• Medications: Discontinue or substitute offending agent 1
• UTI: Appropriate antibiotics 1
• Constipation: Disimpaction and bowel regimen 1
• Sleep apnea: ENT referral for adenotonsillectomy 1
• Diabetes insipidus: Desmopressin replacement and tumor treatment 5

Effective treatment of the underlying problem eliminates the enuresis in secondary cases 1. Standard enuresis treatments (alarm therapy, desmopressin) should only be initiated after addressing secondary causes 1.