What is short contact therapy?

Short Contact Therapy: Definition and Clinical Application

Short contact therapy (SCT) is a treatment strategy where a topical medication is applied to the skin for a brief, defined period (typically 20-60 minutes) and then completely removed with washing, rather than leaving it on the skin continuously. 1

Primary Applications

Psoriasis Treatment with Anthralin

• Anthralin is most commonly used as short-contact therapy in the outpatient setting, starting at 1% concentration with increasing concentration over time as tolerated 1
• The typical contact time is 20-30 minutes before washing off 1
• This approach was developed primarily to address anthralin's most problematic side effects: skin irritation and staining of lesional and adjoining skin, nails, clothing, and other objects 1
• Patients who use short-contact therapy experience significantly less irritation of affected and surrounding skin compared to those who leave anthralin on without washing it off (exposure ≤2 hours vs. continuous application) 1

Acne Treatment with Retinoids

• SCT with tretinoin involves applying the medication once daily for 30-60 minutes, then completely removing it with a gentle cleanser 2, 3
• This approach was developed because irritant contact dermatitis occurs in approximately 85-95% of patients treated with standard tretinoin application, with moderate to severe dermatitis in 20% of cases 3, 4
• In a study of 74 patients using 0.05% tretinoin cream as SCT for 30 minutes daily, only 17.6% developed mild skin irritation and only 5.4% discontinued due to severe irritation 3
• A randomized controlled trial (the MASCOTTE study) demonstrated that tretinoin/clindamycin/glycolic acid gel applied as SCT had significantly better tolerability than standard application (tolerability scores: 1.3 vs 3.1 at week 2, P=0.028) while maintaining comparable or superior clinical efficacy 2

Other Dermatologic Applications

• Tazarotene (topical retinoid for psoriasis) can be used as short-contact treatment for 30-60 minutes to reduce local irritation in lesional and perilesional skin 1
• This strategy can be combined with moisturizers or topical corticosteroids to further minimize irritation 1

Mechanism of Benefit

The rationale for SCT is straightforward: sufficient therapeutic penetration occurs during the brief contact period to achieve clinical efficacy, while limiting the duration of exposure reduces cumulative irritation and other adverse effects 1, 2, 3. This is particularly important for medications like anthralin and retinoids that have inherent irritant properties 4.

Clinical Outcomes

Efficacy Preservation

• For anthralin in psoriasis, SCT efficacy appears comparable to more potent topical corticosteroids or vitamin D derivatives when used as monotherapy 1
• For tretinoin in acne, SCT efficacy is superimposable to standard application modality, with 55.4% of patients achieving ≥50% improvement from baseline 3
• The MASCOTTE trial showed 55% reduction in acne severity (GAGS score) with SCT versus standard application 2

Tolerability Advantages

• SCT markedly improves patient adherence and compliance due to reduced side effects 3
• Dropout rates due to irritation are substantially lower with SCT: 5.4% with tretinoin SCT versus the typical 15% discontinuation rate with standard tretinoin application 3
• For anthralin, SCT reduces both staining and irritation compared to overnight application while maintaining equal effectiveness 5

Practical Implementation

Anthralin Protocol

• Start at 1% concentration 1
• Apply for 20-30 minutes 1
• Increase concentration gradually over time as tolerated 1
• Protect surrounding normal skin with zinc oxide paste if psoriatic plaques are well-defined 1
• Apply with caution to face and intertriginous areas due to severe irritation risk 1

Retinoid Protocol

• Apply once daily (typically evening application) 2, 3
• Leave on for 30-60 minutes 1, 2, 3
• Remove completely using a non-aggressive or gentle cleanser 2, 3
• Can be combined with moisturizers or topical corticosteroids for additional irritation reduction 1

Important Caveats

• SCT is not appropriate for all topical medications—it is specifically indicated for agents with significant irritant potential like anthralin, tretinoin, and tazarotene 1, 4
• The approach requires patient education and compliance with the washing step; failure to remove the medication negates the tolerability benefit 2
• For anthralin, optimal regimens require careful balancing of both exposure time and concentration 1