PDE4 Inhibitor-Responsive Dermatoses: An Emerging Concept in Dermatology

J Clin Aesthet Dermatol. 2025;18(12):50–65.

by Courtney A. Chau, BS; Hilary E. Baldwin, MD; James Q. Del Rosso, DO; Julie C. Harper, MD; Edward Lain, MD, MBA; Todd Schlesinger, MD; Ali Shahbaz, MD; Heather Woolery-Lloyd, MD; Jennifer C. Jaworski, MS; Melissa S. Seal, PhD; Diane Hanna, DNP, DCNP; and Peter Lio, MD

Ms. Chau is with the Icahn School of Medicine at Mount Sinai in New York, New York. Dr. Baldwin is with the Department of Dermatology at Rutgers University Robert Wood Johnson Medical Center in New Brunswick, New Jersey. Dr. Del Rosso is with JDR Dermatology Research Center, LLC in Las Vegas, Nevada and Advanced Dermatology and Cosmetic Surgery in Maitland, Florida. Dr. Harper is with the Dermatology and Skin Care Center of Birmingham in Birmingham, Alabama. Dr. Lain is with Sanova Dermatology in Austin, Texas. Dr. Schlesinger is with Clinical Research Center of the Carolinas in Charleston, South Carolina. Dr. Shahbaz is with Texas A&M School of Medicine in Bryan, Texas and Westlake Dermatology and Cosmetic Surgery in Austin, Texas. Dr. Woolery-Lloyd is with the Dr. Philip Frost Department of Dermatology and Cutaneous Surgery at the University of Miami Miller School of Medicine in Miami, Florida. Ms. Jaworski, Dr. Seal, and Dr. Hanna are with Arcutis Biotherapeutics, Inc. in Westlake Village, California. Dr. Lio is with the Departments of Dermatology & Pediatrics at Northwestern University Feinberg School of Medicine in Chicago, Illinois.

FUNDING: Editorial assistance was provided by Ashfield MedComms, an Inizio Company, and was supported by Arcutis Biotherapeutics, Inc.

DISCLOSURES: Courtney A. Chau has no conflicts of interest to disclose. Hilary E. Baldwin has served as investigator, speaker, and/or advisor for Almirall, Arcutis, Beiersdorf, Botanix, Galderma, Journey Medical Corporation, L’Oréal, La Roche-Posay, Ortho Dermatologics, Phyla Skincare, and Sun Pharma. James Q. Del Rosso reports receiving investigator fees, speaker fees, clinical research grants, and/or honoraria from Aclaris, Almirall, Amgen, AnaptysBio, Arcutis, Athēnix, Biofrontera, BioPharmX, Biorasi, BlueCreek Dermatologics, BMS, Botanix, Brickell Biotech, Cara Therapeutics, Cassiopea SpA, Dermata, Dermavant, Dermira, Encore Dermatology, Evommune, Ferndale Laboratories, Foamix, Galderma, Genentech, Incyte, JEM Health, La Roche-Posay/L’Oréal, LEO Pharma, Lilly, Mayne Pharma, Menlo Therapeutics, Novan, Ortho Dermatologics, Pfizer, Promius Pharma, Ralexar, Regeneron/Sanofi Genzyme, Sebacia, Senté, Sol-Gel Technologies, Sonoma Pharmaceuticals, Sun Pharmaceuticals, Trevi Therapeutics, UCB, Unilever Home & Personal Care, Verrica, and Viamet, and receiving salary as an employee of Regeneron Pharmaceuticals. Julie C. Harper reports consulting fees and/or honoraria from Almirall, Arcutis, Bioderma, Beiersdorf, Bubble Skincare, Cutera, Galderma, Journey Medical Corporation, L’Oréal, Nutrafol, Ortho Dermatologics, and Sun Pharma. Edward Lain is an investigator for and has received grants/research funding and honoraria from Arcutis. Todd Schlesinger is an investigator, speaker, and/or consultant for AbbVie, Allergan, Almirall, Apogee Therapeutics, Arcutis, ASLAN Pharmaceuticals, Beiersdorf, BENEV, Biofrontera, BMS, Boehringer Ingelheim, Cara Therapeutics, Castle Biosciences, ChemoCentryx, Coherus, Concentrics, Concert Pharmaceuticals (acquired by SUN Pharma), Crown Aesthetics, Cutanea, Dermavant, Dermsquared, ExoCoBio, Flint Clinical, Galderma, Genentech, Highlightll, HTL Biotechnology, Incyte, Janssen, L’Oréal, LEO Pharma, Lilly, MJH Life Sciences, Nimbus Therapeutics, Novartis, Pfizer, Processa, Prolacta, RBC Consultants, Regeneron, Sanofi, Senté, Sun Pharma, Takeda, Trevi Pharmaceuticals, UCB, and Verrica; is a shareholder of BMS, Lilly, and Remedly; and received a salary from Avant-Health. Ali Shahbaz is an investigator and/or consultant for AbbVie/Allergan, Apogee Therapeutics, Arcutis, Beiersdorf, BMS, Boehringer Ingelheim, Crown Aesthetics, Dermavant, Galderma, Janssen, LEO Pharma, Lilly, Novartis, Sun Pharma, and UCB. Heather Woolery-Lloyd has served as a consultant, speaker, and/or investigator for Allergan, Arcutis, Eirion, Galderma, Incyte, L’Oréal, Lilly, Ortho Dermatologics, Pfizer, Regeneron, and Vyne. Jennifer C. Jaworski, Melissa S. Seal, and Diane Hanna are employees and shareholders of Arcutis Biotherapeutics, Inc. Peter Lio reports honoraria for participation in speakers bureaus for AbbVie, Arcutis, Galderma, Hyphens Pharma, Incyte, La Roche-Posay/L’Oréal, Lilly, Pfizer, Pierre Fabre, Regeneron/Sanofi Genzyme, and Verrica; personal fees for consulting/participation in advisory boards for AbbVie, Almirall, Alphyn Biologics, Amyris, Arcutis, ASLAN Pharmaceuticals, Astria Therapeutics, BMS, Boston Skin Science, Burt’s Bees, Castle Biosciences, Codex Labs, Concerto Biosciences, Dermavant, Galderma, Kenue, L’Oréal, LEO Pharma, Lilly, Lipidor, Merck, Micreos, MyOr Diagnostics, Pelthos Therapeutics, Regeneron/Sanofi Genzyme, Sibel Health, Skinfix, Soteri Skin, Stratum Biosciences, Sun Pharma, Theraplex, Thimble Health, UCB, Unilever, Verdant Scientific, Verrica, and Yobee Care; and stock options with Alphyn Biologics, Codex Labs, Concerto Biosciences, Soteri Skin, Stratum Biosciences, Thimble Health, Yobee Care, and Verdant Scientific. In addition, Dr. Lio has a patent pending for a Theraplex product with royalties paid and is a Board Member and Scientific Advisory Committee Member of the National Eczema Association.

ABSTRACT: Many inflammatory skin conditions share mechanistic pathways involving multiple receptors and cytokines. Perhaps there is no better endorsement of this idea than the foundational concept of “steroid-responsive dermatoses.” Similarly, targeting the phosphodiesterase 4 (PDE4) enzyme, which exists at the crux of several pathways that contribute to inflammatory skin diseases, offers an avenue by which the pathogenesis of multiple conditions may be interrupted. This suggests that PDE4 inhibitors may assume a similar complementary framework for treating “PDE4 inhibitor-responsive dermatoses.” Certain formulations of PDE4 inhibitors (including apremilast, crisaborole, and roflumilast) have undergone rigorous investigation in clinical trials and demonstrated robust efficacy and safety in many dermatologic conditions, achieving United States Food and Drug Administration approval for atopic dermatitis, psoriasis, and seborrheic dermatitis. Herein, we summarize the clinical evidence supporting the emerging concept of “PDE4 inhibitor-responsive dermatoses” and propose that PDE4 inhibition offers an additional pathway to achieving desired clinical outcomes. Keywords: Steroid-responsive dermatoses, PDE4 inhibitor-responsive dermatoses, crisaborole, apremilast, roflumilast, phosphodiesterase 4 inhibition

Introduction

The era of biologics has brought increasingly targeted therapies to dermatology, unlocking the ability to target specific receptors and even single cytokines. Yet, there is no doubt that many inflammatory conditions share mechanistic pathways involving multiple receptors and cytokines. Perhaps there is no better endorsement of this idea than the foundational concept of “steroid-responsive dermatoses,” a term that arose soon after the introduction of steroids to treat skin diseases in the 1950s. The indication of “inflammatory and pruritic manifestations for corticosteroid-responsive dermatoses,” which has been shortened to “steroid-responsive dermatoses,” encompasses the many conditions that exhibit a therapeutic response to corticosteroids. As the number of indications for corticosteroids grew, the term grew more useful.¹ The United States Food and Drug Administration (FDA) has since adopted this term primarily to communicate drug indications; however, this approval pathway now requires specific clinical trials and regulatory endpoints in each disease-specific indication.^2-4 An encompassing term for a wide range of indications, “steroid-responsive dermatoses” demonstrates the interwoven pathogenesis of the dermatoses encountered daily in the practice of dermatology.

Patients, however, increasingly voice concerns regarding continuous long-term use of corticosteroids, a phenomenon that has been characterized in the literature and on media platforms as “steroid phobia.” Estimates of the prevalence of steroid phobia have ranged from 21.0% to as high as 95.7%.^5,6 Concerns related to adverse events include cutaneous events (eg, skin thinning, skin aging, dyspigmentation, striae), systemic events (eg, hypothalamic-pituitary-adrenal axis suppression, increased fracture risk, osteoporosis, stunted growth and development, rebound flare, topical steroid withdrawal [TSW] syndrome, ophthalmic effects), and other unknown long-term effects.^5-10 Meanwhile, nonsteroidal treatment options, which have recently been termed advanced targeted topical (ATT) treatments, for a variety of dermatologic conditions have continued to expand.¹¹ Consensus statements from an expert panel regarding the safety and efficacy of topical corticosteroids (TCS) and newer targeted therapies for inflammatory skin conditions provide a call to action for clinicians to consider newer ATT treatments in patients with chronic inflammatory skin disease.¹⁰ The key components of the consensus statements include that practitioners should exercise caution when prescribing topical or systemic corticosteroids, with use only in acute settings due to the risk of cutaneous and systemic adverse events. Additionally, use of multiple TCS to treat various affected areas of the body can burden the healthcare system and patients. Finally, ATT treatments (including roflumilast, tapinarof, ruxolitinib, and crisaborole) should be considered as alternatives to TCS and can be a safe and effective option.

Analogous to “steroid-responsive dermatoses,” there is an emerging concept involving the nonsteroidal pathway of phosphodiesterase 4 (PDE4) inhibition. In this narrative review, we summarize the existing literature, which demonstrates the potential for many conditions to respond to inhibition of the PDE4 inflammatory pathway, and suggest that it may be time to consider framing a larger group of conditions as being responsive to PDE4 inhibition.

History

Since the introduction of hydrocortisone in the 1950s, TCS have become a mainstay in the field of dermatology for their extensive applications in the treatment of various dermatoses.¹² The anti-inflammatory, vasoconstrictive, antimitotic, and immunosuppressive effects of TCS cast a wide net, interfering with the many pathological mechanisms of “steroid-responsive dermatoses.” This large group of “steroid-responsive dermatoses” includes eczematous, papulosquamous, autoimmune, blistering, vascular, inflammatory, and granulomatous skin conditions, among others.¹

Adverse events associated with TCS became apparent soon after their use expanded in the latter half of the 20th century. Effects such as systemic absorption, adrenal suppression, telangiectasis, purpura, skin atrophy, and striae were already reported by the mid-1970s.¹³ Unsurprisingly, concerns about TCS use have persisted. By 2000, research examined topical steroid phobia among patients with eczema, with one dermatology outpatient center demonstrating that 145 of 200 patients (72.5%) had concerns about using TCS on their own or their child’s skin, leading to nonadherence in 33.1% of these patients.¹⁴ The most prominent concerns among patients were skin thinning and nonspecific long-term adverse events—concerns that remain today, accompanied by concerns of growth stunting, skin aging, dyspigmentation, and the specter of TSW syndrome.^5-9,14

In recent years, the discourse surrounding TSW syndrome has soared. From 2016 to 2020, use of the hashtag “#topicalsteroidwithdrawal” increased 274% on Instagram, Twitter, Facebook, Reddit, LinkedIn, YouTube, and Pinterest.¹⁵ Descriptions of TSW symptoms included edema, widespread erythema, burning pain, skin sensitivity, oozing, skin exfoliation, acneiform papules, and intense itch upon cessation of long-term mid-to-high-potency TCS use.^16,17 A recent study included the first mechanistic evaluation of TSW through metabolomic and transcriptomic evaluation, both in vitro and in patients with atopic dermatitis (AD) reporting TSW symptoms following glucocorticoid exposure, and identified TSW as an iatrogenic dermatopathy distinct from AD in which patients had elevated levels of oxidized nicotinamide adenine dinucleotide (NAD+) in their blood serum and skin as compared to patients without TSW symptoms.¹⁸ Yet, TSW remains a debated and controversial topic in the field of dermatology, and the limited existing research on TSW is of variable quality.¹⁹ Importantly, however, the government of the United Kingdom (through the Medicines and Healthcare Products Regulatory Agency), the National Eczema Society, the British Dermatological Nursing Group, and the British Association of Dermatologists have recognized TSW.^20,21 Additionally, in July 2022, the government of Canada released a safety brief regarding the risk of TSW reactions.²² Although TSW is yet to be officially recognized as an entity in the United States, the National Eczema Association has issued educational information on TSW and highlighted the risks associated with TCS use.^23,24 Concerns regarding corticosteroid use nonetheless support the exploration and expansion of ATT treatment options.

PDE4 inhibition for the treatment of dermatological diseases was born out of the work of Jon Hanifin, starting in the late 1980s. In 1988, Hanifin characterized cyclic adenosine monophosphate (cAMP)-PDE forms in monocytes and lymphocytes, exploring the potential role of abnormal PDE elevation in inflammatory response in AD.²⁵ Playing an important role in degradation of cAMP, PDE4 acts to regulate inflammatory activity in many immune cells, such as T cells, neutrophils, dendritic cells, monocytes, macrophages, and eosinophils (Figure 1).^26-30 As such, PDE4 inhibition attenuates the production and release of cytokines and chemokines, influencing inflammation and chemotaxis by interfering with a variety of downstream pathways.^26,31 Inhibition has also been shown to directly reduce the activation of dermal sensory neurons that mediate the itch sensation as well as normalization of keratinocyte activation and differentiation that causes epidermal barrier dysfunction.^30,32-38 Additionally, PDE4 inhibition with roflumilast has been shown to promote melanocyte proliferation, increase melanogenic gene and protein expression in cultured melanocytes, and protect melanocytes from apoptosis.^39,40 Thus, targeting this enzyme that exists at the crux of several mechanistic pathways offers an avenue by which the pathogenesis of multiple conditions may be interrupted.

Hanifin’s exploration continued throughout the 1990s with investigations of increased cAMP-PDE activity in leukocytes of patients with AD, as well as of the in vivo and in vitro anti-inflammatory efficacy of PDE4 inhibitors for AD.^41,42 This was demonstrated with twice-daily (BID) application of a topical PDE4 inhibitor (CP 80,633) in patients with AD for 28 days, resulting in significantly decreased inflammation within 3 days and overall reductions in erythema, induration, and excoriations.⁴² Certain formulations of PDE4 inhibitors have since undergone rigorous investigation in clinical trials and demonstrated robust efficacy and safety, achieving FDA approval for apremilast, crisaborole, and roflumilast. The structural properties of these PDE4 inhibitors inform how they bind to the active site in PDE4 and impacts potency, function, and clinical efficacy.⁴³

PDE4 Inhibitors with approved indications in dermatology

Apremilast. Apremilast, a small-molecule oral PDE4 inhibitor, was first approved by the FDA in 2014 for adults with active psoriatic arthritis. Its indications now include adults and children (aged 6 years or older and weighing at least 20kg) with plaque psoriasis who are candidates for phototherapy or systemic therapy and adults with oral ulcers associated with Behçet’s disease at doses ranging from 10 to 30mg.^44,45

In randomized control trials, apremilast has demonstrated efficacy in achieving at least 75% improvement in Psoriasis Area and Severity Index (PASI-75) after 16 weeks in 29% to 41% of participants with psoriasis at a dosage of 30mg twice per day (BID) and 29% and 11% at dosages of 20mg and 10mg BID, respectively.^46-48 For psoriatic arthritis, 16 weeks of treatment has demonstrated ≥20% improvement in American College of Rheumatology response criteria (ACR20) among 28% to 37% of patients receiving a dose of 20mg BID, and 32% to 41% of patients at 30mg BID.^49,50 After 52 weeks, a sustained response to treatment has been observed, with 75% of participants in the ESTEEM 1 trial achieving PASI-70 and over 50% achieving ACR20 in the PALACE 2 trial.^47,49,50

While apremilast has demonstrated marked efficacy in clinical trials, several factors modulate patient outcomes in the clinical setting. Continued use of apremilast in patient populations is complicated by its dosing and adverse events. Upon treatment initiation, the dose can be gradually titrated over 5 days to reach the desired daily dosing schedule. Additionally, dosage is maintained at BID (with the exception of patients with impaired renal function).⁴⁵ The complicated and frequent nature of dosing may reduce patient adherence or result in treatment switching. Additionally, the most commonly reported adverse events include weight loss and gastrointestinal symptoms (nausea, vomiting, and diarrhea). To a lesser degree, patients may experience headache and upper respiratory tract infection.^45,47-51 Much less frequently, depression and suicidal ideation have also been reported.^45,49,51 Although most adverse events are seemingly mild, they may contribute to discontinuation of treatment. In a retrospective review of 2841 patients receiving apremilast, adherence to apremilast over a 24-month period was estimated at 22.8%.⁵² Treatment persistence studies have estimated low drug persistence, with 6-month and 1-year drug survival rates ranging from 50.3% to 69.5% and 31.3% to 34.7%, respectively. The 2 primary reasons for discontinuation were lack or loss of efficacy and adverse events.^51,53 Less frequently, discontinuation was related to pregnancy plans, as pregnancy and breastfeeding are contraindications to apremilast treatment.^45,53

Regardless, apremilast is efficacious and relatively safe for its indications, demonstrating mostly mild-to-moderate adverse events for patients as young as 6 years of age. Additionally, it may be a more accessible option than biologics for some patients.⁵²

Crisaborole. Crisaborole is a topical treatment that was approved by the FDA in 2016. Crisaborole is indicated for mild-to-moderate AD in adult and pediatric patients aged 3 months and older.⁵⁴ In a pooled analysis of 8 randomized control trials, patients undergoing 4-week treatment with crisaborole BID demonstrated significant improvements in the Pruritus Numerical Rating Scale (NRS), Patient-Oriented Eczema Measure (POEM), Eczema Area and Severity Index (EASI), Investigator Global Assessment (IGA), Dermatology Life Quality Index (DLQI), and Dermatitis Family Impact Questionnaire (DFI) compared with 4 weeks of vehicle treatment. Additionally, patients treated with crisaborole achieved ≥75% improvement in EASI (EASI-75) at a higher rate (relative risk of 1.71) than vehicle. Importantly, there was no difference in the incidence of adverse events between crisaborole and vehicle-treated groups.⁵⁵ With regard to long-term outcomes, studies of up to 52 weeks have demonstrated continued efficacy.^56-58 At 52 weeks, patients treated with crisaborole BID had a longer median flare-free interval, more flare-free days (on average), and fewer flares (on average) than patients treated with vehicle.⁵⁶

Adverse events associated with crisaborole include AD, application site pain, application site infection, gastrointestinal disorders, upper respiratory tract infection, and nasopharyngitis; although, studies of these adverse events considered them unrelated to treatment, and there is little evidence of serious adverse events with crisaborole use.^57-59 Additionally, systemic exposure of crisaborole is minimal, as it is rapidly metabolized to inactive products; however, systemic exposure increases with increased application area.⁵⁸ Crisaborole provides a nonsteroidal treatment option for patients with AD as young as 3 months of age.

Limitations of crisaborole use include adherence, hypersensitivity, and local tolerability. As a topical ointment, crisaborole is subject to the well-known phenomenon of nonadherence, which is often a result of inconvenience.^60,61 Additionally, hypersensitivity reactions to crisaborole are contraindications to its use, although such reactions occur in a minority of patients and are typically mild or moderate.^54,57-59 Thirdly, stinging and burning at the application site, while reported at relatively low levels in clinical trials, have been observed to be more common in the postmarketing phase, affecting upwards of 30% of patients in some reports.⁶²

Roflumilast. Roflumilast is a PDE4 inhibitor originally approved by the FDA in 2011 as an oral formulation for reducing the risk of chronic obstructive pulmonary disease (COPD) exacerbations.⁶³ In recent years, topical roflumilast has been approved for several dermatologic indications. The cream formulation is approved for psoriasis in patients aged 6 years and older at 0.3% and for AD in patients aged 6 years and older and 2-5 years at 0.15% and 0.05%, respectively.^64,65 An additional trial of roflumilast cream 0.05% is underway in patients with AD aged 3 to 24 months.⁶⁶ The foam preparation (0.3%) is approved for patients with seborrheic dermatitis aged 9 years and older and for patients with psoriasis of the scalp and body aged 12 years and older.⁶⁷ Once-daily (QD) topical roflumilast has demonstrated substantial efficacy in a recent meta-analysis of randomized controlled trials on roflumilast cream 0.3% for psoriasis. Patients saw significant achievement of IGA success (ie, clear or almost clear with ≥2-grade improvement from baseline; relative risk of 5.07 compared to vehicle) and PASI-75 (relative risk of 4.48 compared to vehicle) at 8 weeks.⁶⁸ Patients with seborrheic dermatitis treated with roflumilast foam 0.3% QD demonstrated up to 43.0%, 73.1%, and 73.8% achievement of IGA success at 2, 4, and 8 weeks, respectively, in Phase II and III trials.^69,70 Similarly, the INTEGUMENT trials of roflumilast cream 0.15% QD in patients aged ≥6 years with AD demonstrated up to 43.2% achieved EASI-75 by 4 weeks of treatment.⁷¹ Topical roflumilast was also well tolerated and demonstrated safety in long-term trials of up to 52 weeks.^72,73 The most common adverse events reported were mild or moderate, and included diarrhea, nausea, headache, upper respiratory tract infections, and nasopharyngitis.^69-74

The QD dosing regimen offers more convenience than other topical PDE4 inhibitors and is well tolerated, with patient-reported rates of stinging and burning of <2%. Additionally, the cream roflumilast formulation is approved and efficacious in intertriginous areas, providing a well-tolerated treatment option for patients with intertriginous involvement.⁷²

An oral formulation of roflumilast has been explored for the treatment of psoriasis, demonstrating PASI-75 achievement in 44% of patients at 24 weeks, although with more adverse events, specifically gastrointestinal adverse events, than the topical formulation.⁷⁵

PDE4 Inhibitors in other dermatologic conditions

PDE4 inhibitors continue to be explored for their potential applications in a wide range of inflammatory conditions. Table 1 summarizes several reports of other dermatologic conditions that have responded to PDE4 inhibition, identified through a nonsystematic search of PubMed using terms including PDE4 inhibition, case reports, clinical trial, and dermatologic conditions, conducted on February 28, 2025. Reports published up to the date of the search were selected based on novelty, relevance to the field, and the relative unmet medical need for a particular indication, with priority given to reports containing higher levels of evidence. The level of evidence varies from single case reports to randomized controlled trials, and the strength of the conclusions drawn from these reports is commensurate with these differences.

An Emerging Concept: “PDE4-Responsive Dermatoses”

Given the role of PDE4 in the pathogenesis of so many inflammatory skin conditions and the continued exploration into the growing number of potential indications for PDE4 inhibitors, the concept of “PDE4 inhibitor-responsive dermatoses” may be a useful, modern way of thinking about many of the common inflammatory skin conditions that are seen in dermatology each day.

Moreover, PDE4 inhibitors are generally well tolerated and have demonstrated remarkable safety among adult and pediatric patients. Not only are they efficacious, but they are also useful in body areas that may be challenging for TCS, such as facial, eyelid, genital, and flexural areas, provided they are appropriately formulated for these areas. Therefore, PDE4 inhibitors complement the existing concept of “steroid-responsive dermatoses,” offering an additional tool to potentially reach desired clinical outcomes.

Conclusion

The concept of “steroid-responsive dermatoses” has persisted because of its utility in treating a wide range of inflammatory conditions, despite recent advances in the availability of ATT treatments. The field may benefit from welcoming the nonsteroidal complementary framework of “PDE4 inhibitor-responsive dermatoses.” In clinical practice, for cases of overlapping conditions, unclear diagnoses, inadequate responses to targeted agents, and patients for whom targeted agents may not be suitable, PDE4 inhibitors pose an ATT option that can play a key role in the broader treatment of inflammation. TCS have a place in dermatology to address acute self-limiting presentations; however, it seems that PDE4 inhibitors can safely and effectively assume a role analogous to that of TCS in treating a wide variety of inflammatory conditions encountered in dermatology daily. We look forward to the volume and quality of the evidence base for this concept grow and evolve.

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