What is the standard of care for assessing rashes in psychiatric patients, should I refer them to their Primary Care Physician (PCP) or a dermatologist?

Standard of Care for Rash Assessment in Psychiatry

As a psychiatrist, you should perform an initial assessment to identify concerning features that require urgent specialist referral, but definitive diagnosis and management of most rashes falls outside psychiatric scope and should be referred to dermatology or primary care. 1

Your Role: Initial Triage and Red Flag Identification

Immediate Same-Day Dermatology Referral Required For:

• Blisters covering ≥1% body surface area 1
• Any rash with mucosal involvement (oral, genital, ocular lesions) 1
• Rash covering ≥30% body surface area 1
• Skin pain with or without blisters (excluding dermatomal shingles) 1
• Necrosis, petechiae, or purpuric lesions 1
• Signs of cellulitis or infection (warmth, erythema, swelling, pain) 1
• Suspected Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis - these patients require immediate hospitalization 1

Non-Urgent Dermatology Referral Appropriate For:

• Unclear diagnosis after initial assessment 1
• Grade 2 rash that is worsening despite basic measures 1
• Unusual appearance or distribution of lesions 1
• Any atypical dermatologic manifestation potentially unrelated to psychiatric medications 1

Psychiatric Medication-Related Rashes: What You Need to Know

Common Culprits in Psychiatry:

Psychotropic medications cause adverse cutaneous reactions in approximately 2-5% of patients, with mood stabilizers carrying the highest risk 2. The most implicated psychiatric drugs for severe reactions (DRESS syndrome) include:

• Carbamazepine (highest risk)
• Lamotrigine
• Phenytoin
• Valproate
• Phenobarbital 3

Your Assessment Should Document:

• Timing of rash onset relative to medication initiation (most drug reactions occur within days to weeks) 2, 4
• Presence of systemic symptoms: fever, lymphadenopathy, facial edema, arthralgias 3
• Eosinophilia on laboratory testing (if DRESS suspected) 3
• Percentage of body surface area involved 1
• Presence/absence of mucosal involvement 1

When You Can Manage vs. Must Refer

You Should NOT Attempt to Diagnose or Treat:

The evidence is clear that dermatologic diagnosis requires specialized training 1. Even oncologists managing EGFR-inhibitor rashes—who see these reactions frequently—are instructed to refer grade 2 or higher reactions to dermatology unless they have "in-depth knowledge and extensive clinical experience in the field of toxic effects of the skin" 1.

Your Immediate Actions:

1. Photograph the rash before any treatment for documentation 1
2. Discontinue the suspected causative psychiatric medication immediately if severe reaction suspected 3
3. Arrange urgent/emergent dermatology consultation based on red flags above 1
4. Consider hospitalization for suspected DRESS, SJS/TEN, or systemic involvement 1, 3

Critical Pitfall to Avoid

Do NOT start corticosteroids before dermatology/ophthalmology evaluation if there is any eye involvement, as this may worsen infectious causes (herpetic keratitis) or mask accurate diagnosis 1. This principle extends to other presentations where infection must be ruled out first 1.

Addressing Psychiatric Comorbidity

While the rash itself requires dermatologic expertise, you maintain responsibility for:

• Screening for anxiety and depression related to visible skin disease, which significantly impacts quality of life 1
• Managing psychiatric symptoms that may worsen with disfiguring rashes 1, 5
• Coordinating care between dermatology and psychiatry for patients who refuse psychiatric referral 4, 6
• Selecting alternative psychiatric medications after DRESS or severe reactions, avoiding cross-reactive agents 3

The standard is collaborative care: you identify concerning features and refer appropriately, while dermatology provides definitive diagnosis and dermatologic treatment 1, 4, 5, 6.