Nail Psoriasis

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Overview of Nail Psoriasis

Psoriatic nail disease has many clinical signs. Most psoriatic nail disease occurs in patients with clinically evident psoriasis; it only occurs in less than 5% of patients with no other cutaneous findings of psoriasis.

An estimated 10-55% of all patients with psoriasis have psoriatic nail disease, and approximately 7 million people in the United States have psoriasis. About 150,000-260,000 new cases of psoriasis are diagnosed each year. US physicians see 1.5 million patients with psoriasis per year.

Severe psoriatic nail disease can lead to functional and social impairments if left untreated.[1, 2]

See the images of psoriatic nail disease below.



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Courtesy of Hon Pak, MD.



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Classic distal interphalangeal joint involvement in psoriatic arthritis.



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This patient has extensive psoriasis, nail involvement, and joint pain.

See 15 Fingernail Abnormalities: Nail the Diagnosis, a Critical Images slideshow, to help identify conditions associated with various nail abnormalities.

For patient education information, see the Psoriasis Center and Arthritis Center, as well as Psoriasis, Types of Psoriasis, Understanding Psoriasis Medications, and Psoriatic Arthritis.

Pathophysiology of Nail Psoriasis

The pathogenesis of the psoriatic nail disorder is not completely known. Nail psoriasis may be due to a combination of genetic, environmental, and immune factors. A well-known fact is that a familial aggregation of psoriasis exists. Studies have linked psoriasis with certain human leukocyte antigen subtypes (eg, Cw6, B13, Bw57, Cw2, Cw11, B27). A T-cell–mediated inflammatory process is being investigated as part of the pathogenesis of psoriasis.

Epidemiology of Nail Psoriasis

Psoriatic nail disease occurs in 10-55% of all patients with psoriasis, and approximately 7 million people in the United States have psoriasis (psoriasis affects 2-3% of the US population). Less than 5% of psoriatic nail disease cases occur in patients without other cutaneous findings of psoriasis. About 10-20% of people with psoriasis also have psoriatic arthritis, and nail changes are seen in 53-86% of patients with psoriatic arthritis.

Psoriasis tends to run in families. In Farber's questionnaire study of 2100 patients,[3] 36% of patients reported the presence of psoriasis in at least 1 relative. Among siblings, 8% are affected if neither parent has psoriasis. This percentage increases to 16-25% if 1 parent or sibling has the disease, and it reaches up to 75% if both parents are affected. If 1 twin has psoriasis, the other twin is at an increased risk of having psoriasis (25% for fraternal twins, 65% for identical twins).

In Scandinavia, the prevalence rate of nail psoriasis for adults with psoriasis approaches 5%. The prevalence increases with the age of the population studied.

Psoriatic nail disease is not associated with mortality. In severe cases, patients may have functional and psychosocial impairments.

Males and females are affected equally by nail psoriasis, and the prevalence of nail psoriasis increases with the age of the population studied.

Clinical Presentation of Nail Psoriasis

Patient history

Most psoriatic nail disease occurs in people with clinically evident psoriasis. The diagnosis of psoriatic nail disease without cutaneous psoriasis can be challenging because of the low index of suspicion and the lack of personal/family history of psoriasis.

A retrospective study from 2014 reports that nail involvement in psoriasis is a significant predictor of the patient also having psoriatic arthritis.[4] The study looked at retrospective data from three German cross-sectional independent national studies on patients with psoriasis and psoriatic arthritis. Data on the patient’s history of psoriasis and psoriatic arthritis, clinical findings, nail involvement, and patient- and practitioner-reported outcomes were collected from standardized questionnaires. In the results, the regression model of 4146 patients indicated one of the strongest predictors of concomitant psoriatic arthritis was nail involvement. Balestri et al also suggest nail psoriasis as a risk factor for subclinical psoriatic arthritis, reporting that 50% of subjects with nail psoriasis had interphalangeal stiffness, pain, and swelling.[5]

Choi et al sought to determine whether psoriatic nail features were associated with nail psoriasis or cutaneous psoriasis disease severity.[6] Studies results indicated nail fold psoriasis and subungual hyperkeratosis were significantly associated with disease severity in both cutaneous psoriasis and nail psoriasis.

Physical examination

The clinical findings associated with psoriatic nail disease correlate with the anatomical location of the nail unit that is affected by the disease. The nail unit is composed of the nail plate, the nail bed, the hyponychium, the nail matrix, the nail folds, the cuticle, the anchoring portion of the nail bed, and the distal phalangeal bones (see the images below). The nail plate is the largest component of the nail unit. The nail matrix gives rise to the nail plate.

Any defect to the matrix results in onychodystrophy of the growing nail plate. The proximal nail matrix forms the dorsal portion of the nail plate, whereas the distal matrix forms the ventral part of the nail plate. The clinical presentation may vary depending on the location and the severity of inflammation of the affected nail unit.[7] See the images below.



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Anatomy of the nail, superior view.



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Anatomy of the nail, sagittal view.

Oil drop or salmon patch of the nail bed

This lesion is a translucent, yellow-red discoloration in the nail bed resembling a drop of oil beneath the nail plate. This patch is the most diagnostic sign of nail psoriasis.[8]

Pitting of the proximal nail matrix

Pitting is a result of the loss of parakeratotic cells from the surface of the nail plate.

Beau lines of the proximal nail matrix

These lines are transverse lines in the nails due to intermittent inflammation causing growth arrest lines.

Leukonychia of the midmatrix

Leukonychia consists of areas of white nail plate due to foci of parakeratosis within the body of the nail plate.

Subungual hyperkeratosis of the hyponychium

Subungual hyperkeratosis affects the nail bed and the hyponychium. Excessive proliferation of the nail bed can lead to onycholysis.

Onycholysis of the nail bed and nail hyponychium

Onycholysis is a white area of the nail plate due to a functional separation of the nail plate from its underlying attachment to the nail bed. It usually starts distally and progresses proximally, causing a traumatic uplifting of the distal nail plate. Secondary microbial colonization may occur.

Nail plate crumbling

Nail plate weakening due to disease of the underlying structures causes this condition.

Splinter hemorrhage/dilated tortuous capillaries in the dermal papillae

Splinter hemorrhages are longitudinal black lines due to minute foci of capillary hemorrhage between the nail bed and the nail plate. This is analogous to the Auspitz sign of cutaneous psoriasis, which is the pinpoint bleeding seen beneath the psoriatic plaques.

Spotted lunula/distal matrix

This is an erythematous patch of the lunula.

Classification of nail psoriasis

Most people with psoriatic arthritis have nail changes that can be classified as follows (see the images below):

See the images below.



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Classic distal interphalangeal joint involvement in psoriatic arthritis.



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This patient has extensive psoriasis, nail involvement, and joint pain.

Etiology of Nail Psoriasis

Psoriatic nail disease may be due to a combination of genetic, environmental, and immune factors. A well-known fact is that a familial aggregation of psoriasis exists. Recent studies have linked psoriasis with certain human leukocyte antigen subtypes (eg, Cw6, B13, Bw57, Cw2, Cw11, B27). A T-cell–mediated inflammatory processing is being investigated as part of the pathogenesis of psoriasis.

Differential Diagnosis

The differential diagnosis of nail psoriasis includes the following:

Other problems to be considered include idiopathic trachyonychia and punctate keratoderma.

Skin Biopsy

A nail biopsy is needed to confirm the diagnosis of nail psoriasis in some cases and is usually taken from the nail bed.

Histologic Findings

Psoriasis can affect any part of the nail unit. Most changes occur in the nail plate. Histologic findings of nail psoriasis include mild-to-moderate hyperkeratosis, hypergranulosis, serum globules and hemorrhage in the corneum layer, papillomatous epidermal hyperplasia, and spongiosis.

Overview of Treatment of Nail Psoriasis

Many treatment options are available after the diagnosis of nail psoriasis is made. The treatments focus on improvement of the functional and psychosocial aspects of psoriatic nail disease.

The treatment options for nail psoriasis include topical corticosteroids, intralesional corticosteroids, psoralen plus ultraviolet light A (PUVA),[9] topical fluorouracil,[10] topical calcipotriol,[11] topical anthralin,[12] topical tazarotene,[13, 14] topical cyclosporine,[15] avulsion therapy,[16] and systemic therapy for severe cases. Onychomycosis (if present) requires antifungal therapy for improvement. Laser and light therapies have emerged as possible cost-efficient, in-office treatments; however, large-scale trials are needed, particularly in consideration for the effects in combination with other current therapies.[17]

For preventive care, keep the nails dry and protect them from trauma to avoid the Koebner effect and possible secondary microbial colonization. In areas of onycholysis, the nail plate should be trimmed to the point of separation for medications to be effective.

At present, no definitive and curative treatment has been agreed upon by medical experts. Discuss all treatment options for psoriatic nail disease with the patient, and choose the best individually tailored regimen.

Corticosteroids

Topical treatment with high-potency corticosteroid solution or ointment under occlusion with cellophane wrap at bedtime can improve nail psoriasis. Avoid long, continuous therapy with corticosteroids to avoid tachyphylaxis. Also, avoid prolonged occlusion (not to exceed 2 wk). A topical preparation of a combination of high-potency corticosteroid and calcipotriol may benefit some patients.[18]

5-Fluorouracil

Topical 1% 5-fluorouracil solution or 5% cream applied twice daily to the matrix area for 6 months without occlusion improves pitting and subungual hyperkeratosis.

Phototherapy

Psoralen plus ultraviolet light A (PUVA) is very effective for cutaneous psoriasis and can improve nail psoriasis. Both oral and topical PUVA therapies have improved nail psoriasis in 3-6 months. A possible adverse effect of PUVA may be nail discoloration.

Guidelines on the management and treatment of psoriasis with phototherapy were released in September 2019 by the American Academy of Dermatology and the National Psoriasis Foundation.[19]

Narrowband ultraviolet B phototherapy

Phototherapy using narrowband ultraviolet B (NB-UVB) is recommended as monotherapy for adults with plaque psoriasis.

For adults with generalized plaque psoriasis, the recommended NB-UVB phototherapy starting dose should be based on the minimal erythema dose or it should be determined based on a fixed-dose or skin-phototype protocol.

For adults with generalized plaque psoriasis, a treatment phase of thrice-weekly dosing of NB-UVB phototherapy is recommended.

For adults with psoriasis, treatment with short-term psoralen plus ultraviolet A (PUVA) monotherapy is more effective than NB-UVB.

Owing to its increased safety, higher convenience, and lower cost, NB-UVB is preferred over PUVA monotherapy for psoriasis in adults, even though it is less effective.

In adults with generalized plaque psoriasis, NB-UVB is recommended over broadband ultraviolet B (BB-UVB) monotherapy.

Treatment with NB-UVB monotherapy is recommended for guttate psoriasis patients, regardless of their age.

For appropriate patients with generalized plaque psoriasis, home-based NB-UVB phototherapy is recommended as an alternative to in-office NB-UVB phototherapy.

Treatment with NB-UVB phototherapy is recommended for pregnant patients who have guttate psoriasis or generalized plaque psoriasis.

As a measure to possibly improve efficacy, NB-UVB phototherapy can be safely augmented with concomitant topical therapy using retinoids, vitamin D analogues, and corticosteroids.

Oral retinoids can be combined with NB-UVB phototherapy in appropriate patients with generalized plaque psoriasis if they have not responded adequately to monotherapy.

Owing to an increased risk of developing skin cancer, long-term combination therapy with NB-UVB and cyclosporine is not recommended for adults with generalized plaque psoriasis.

Apremilast combined with NB-UVB phototherapy can be considered for adult patients with generalized plaque psoriasis if they have not responded adequately to monotherapy.

To reduce the risk of genital skin cancer, all patients receiving NB-UVB phototherapy should be provided genital shielding.

To reduce the risk of ocular toxicity, all patients receiving NB-UVB phototherapy should be provided eye protection with goggles.

Owing to the risk of photocarcinogenesis, use caution when administering NB-UVB phototherapy to patients with a history of melanoma or multiple nonmelanoma skin cancers, arsenic intake, or prior exposure to ionizing radiation.

Folate supplementation is recommended for females of childbearing age who are receiving NB-UVB phototherapy.

To maintain the clinical response from NB-UVB phototherapy, maintenance therapy can be considered.

BB-UVB phototherapy

In adults with generalized plaque psoriasis, BB-UVB phototherapy is recommended as monotherapy if NB-UVB is not available.

In adults with generalized plaque psoriasis, BB-UVB monotherapy is considered less efficacious than NB-UVB or oral PUVA monotherapy.

Monotherapy with BB-UVB may be considered for adults with guttate psoriasis.

To reduce the risk of genital skin cancer, all patients being offered BB-UVB phototherapy should be provided with genital shielding.

To reduce the risk of ocular toxicity, all patients receiving BB-UVB phototherapy should be provided eye protection with goggles.

Owing to the risk of photocarcinogenesis, use caution when administering BB-UVB phototherapy to patients with a history of melanoma or multiple nonmelanoma skin cancers, arsenic intake, or prior exposure to ionizing radiation.

Combination therapy with acitretin and BB-UVB can be considered in adults with generalized plaque psoriasis.

Targeted UVB phototherapy

The recommended targeted UVB phototherapy for adults with localized plaque psoriasis (< 10% body surface area), for individual plaque psoriasis lesions, or for patients with more extensive disease includes excimer 308-nm laser, excimer 308-nm light, and targeted NB-UVB 311- to 313-nm light.

For maximal efficacy, the recommended treatment frequency for targeted UVB phototherapy in adults with localized plaque psoriasis is 2-3 times per week, rather than once every 1-2 weeks.

In adults with localized plaque psoriasis, the initial dose of targeted UVB phototherapy is based on the minimal erythema dose or by a fixed-dose or skin-phototype protocol.

For treating localized plaque psoriasis in adults, the most effective targeted UVB phototherapy is excimer 308-nm laser, followed by excimer 308-nm light, followed by localized NB-UVB 311- to 312-nm light.

For adults with plaque psoriasis (including palmoplantar psoriasis), a recommended targeted UVB phototherapy includes excimer 308-nm laser and excimer 308-nm light.

Treatment of plaque psoriasis in adults with excimer 308-nm laser may be combined with topical steroid therapy.

A recommended targeted UVB phototherapy treatment for adults with scalp psoriasis is excimer 308-nm laser.

PUVA therapy

In the treatment of localized plaque psoriasis in adults, particularly those with palmoplantar psoriasis or palmoplantar pustular psoriasis, topical phototherapy with PUVA is deemed superior to NB-UVB 311- to 313-nm light.

A recommended treatment for psoriasis in adults is oral PUVA.

A recommended treatment for moderate-to-severe psoriasis in adults is bath PUVA.

Photodynamic therapy

Photodynamic therapy with either aminolevulinic acid or methyl aminolevulinate is not recommended for adults with localized psoriasis, including the palmoplantar variety or nail psoriasis.

Grenz ray, climatotherapy, visible light, Goeckerman, and pulsed-dye laser therapies

Evidence is insufficient to recommend grenz ray therapy (long-wavelength ionizing radiation) for the treatment of psoriasis.

Sufficient evidence exists to recommend climatotherapy (temporary or permanent relocation geographically) for the treatment of psoriasis.

Evidence is insufficient to recommend the use of visible light (blue or red) as a more effective treatment for psoriasis, except in nail psoriasis.

Sufficient evidence exists to recommend Goeckerman therapy (coal tar in combination with UVB phototherapy) for the treatment of psoriasis.

Pulsed-dye laser can be considered for nail psoriasis.

Triamcinolone

Intralesional triamcinolone acetonide suspension of 2.5 mg/mL into the proximal nail fold is very helpful for nail matrix psoriasis (eg, pitting, ridging, leukonychia). This medication may be administered every 4-6 weeks. The proximal nail fold is sprayed first with a refrigerant spray for anesthesia, and the injection is given with a 30-gauge needle.

Systemic Therapies

Systemic therapies have been used in patients with severe cutaneous psoriasis. Few studies have shown significant improvement in nail psoriasis with long-term results.

Three systemic medications are most commonly used for psoriasis and nail psoriasis: methotrexate, retinoids,[20] and cyclosporine.[21]  All three agents have potential serious adverse effects and toxicities. In most cases, the psoriatic nail disease recurs after the systemic therapy is stopped. Carefully weigh the risk-to-benefit ratio in the treatment of nail psoriasis. Systemic therapies are seldom a first-line therapy for nail psoriasis. Topical treatment with calcipotriol can be used as adjunctive therapy and maintenance therapy with systemic treatment. Biological therapy for psoriasis and psoriatic arthritis may have a significant benefit for some patients with psoriatic nail disease.[22]

In 2017, the US Food and Drug Administration (FDA) approved the addition of moderate-to-severe fingernail psoriasis data to the adalimumab prescribing information, based on results from a phase 3, multicenter, randomized, double-blind, parallel-arm, placebo-controlled clinical trial.[23]

Guidelines on the management and treatment of psoriasis with biologics by the American Academy of Dermatology and the National Psoriasis Foundation [24]

TNF-alpha Inhibitors

Etanercept recommendations are as follows:

Infliximab recommendations are as follows:

Adalimumab recommendations are as follows:

Certolizumab has been approved by the FDA for the treatment of plaque psoriasis, psoriatic arthritis, Crohn disease, ankylosing spondylitis, and rheumatoid arthritis. Approved dosing for moderate-to-severe psoriasis is 400 mg (two 200-mg SC injections) every other week. It is likely to possess class characteristics similar to those of other TNF-alpha inhibitors.

Interleukin-12/23 Inhibitors

Ustekinumab recommendations are as follows:

Interleukin-17 Inhibitors

Secukinumab recommendations are as follows:

Ixekizumab recommendations are as follows:

Brodalumab recommendations are as follows:

Interleukin-23 Inhibitors

Guselkumab recommendations are as follows:

Tildrakizumab recommendations are as follows:

Risankizumab is not approved by the FDA, but it can be used as monotherapy in adults with moderate-to-severe plaque psoriasis. When approved, the dose will likely be 150 mg given by self-administered subcutaneous injections at week 0 and week 4, followed by every 12 weeks.

Avulsion Therapy

Avulsion therapy by chemical or surgical means can be used as an alternative therapy for psoriatic nail disease. Chemical avulsion therapy includes the use of urea ointment in a special compound to the affected nail under occlusion for 7 days, and the nail is removed atraumatically. Chemical avulsion therapy is painless, involves no blood loss, and is less expensive than surgical avulsion.

Surgical avulsion therapy can be performed for psoriatic nail disease when other treatments have failed. During surgery, the matrix can be electively ablated to prevent regrowth of the nail. This procedure is performed under local anesthesia. Inform patients of postoperative discomfort, limitations, and possible physical nail disfigurement.

What is nail psoriasis?What is the pathophysiology of nail psoriasis?What is the prevalence of nail psoriasis?Which patient groups have the highest prevalence of nail psoriasis?What is the morbidity and mortality associated with nail psoriasis?What are the sexual predilections of nail psoriasis?Which clinical history findings are characteristic of nail psoriasis?Which physical findings are characteristic of nail psoriasis?How is oil drop or salmon patch lesions characterized in nail psoriasis?What causes pitting in nail psoriasis?What causes beau lines in nail psoriasis?What causes leukonychia of the midmatrix in nail psoriasis?What causes subungual hyperkeratosis in nail psoriasis?What causes onycholysis in nail psoriasis?What causes nail plate crumbling in nail psoriasis?What causes splinter hemorrhage in nail psoriasis?What is spotted lunula in nail psoriasis?How is nail psoriasis classified?What causes nail psoriasis?Which conditions are included in the differential diagnoses of nail psoriasis?What is the role of biopsy in the workup of nail psoriasis?Which histologic findings are characteristics of nail psoriasis?How is nail psoriasis treated?What is the role of corticosteroids in the treatment of nail psoriasis?What is the role of topical medications in the treatment of nail psoriasis?What is the role of psoralen plus ultraviolet light A (PUVA) in the treatment of nail psoriasis?What are the AAD-NPF guidelines on narrowband ultraviolet B (NB-UVB) phototherapy in the treatment of nail psoriasis?What are the AAD-NPF guidelines on broadband ultraviolet B (BB-UVB) phototherapy in the treatment of nail psoriasis?What are the AAD-NPF guidelines on targeted ultraviolet B (UVB) phototherapy in the treatment of nail psoriasis?What are the AAD-NPF guidelines on psoralen plus ultraviolet light A (PUVA) phototherapy in the treatment of nail psoriasis?What are the AAD-NPF guidelines on photodynamic therapy in the treatment of nail psoriasis?What are the AAD-NPF guidelines on Grenz ray, climatotherapy, visible light, Goeckerman, and pulsed-dye laser therapies in the treatment of nail psoriasis?What is the role of triamcinolone in the treatment of nail psoriasis?What is the role of systemic therapies in the treatment of nail psoriasis?What are the AAD and NPF guidelines on the treatment of nail psoriasis?What is the role of avulsion therapy in the treatment of nail psoriasis?

Author

Cindy Li, DO, Dermatologist and Cosmetic Surgeon, Department of Dermatology, Kaiser Permanente Medical Group

Disclosure: Nothing to disclose.

Coauthor(s)

Richard K Scher, MD, Adjunct Professor of Dermatology, University of North Carolina at Chapel Hill School of Medicine; Professor Emeritus of Dermatology, Columbia University College of Physicians and Surgeons

Disclosure: Nothing to disclose.

Specialty Editors

David F Butler, MD, Former Section Chief of Dermatology, Central Texas Veterans Healthcare System; Professor of Dermatology, Texas A&M University College of Medicine; Founding Chair, Department of Dermatology, Scott and White Clinic

Disclosure: Nothing to disclose.

Chief Editor

William D James, MD, Paul R Gross Professor of Dermatology, Vice-Chairman, Residency Program Director, Department of Dermatology, University of Pennsylvania School of Medicine

Disclosure: Received income in an amount equal to or greater than $250 from: Elsevier; WebMD.

Additional Contributors

Mark G Lebwohl, MD, Chairman, Department of Dermatology, Mount Sinai School of Medicine

Disclosure: Received none from Amgen for consultant & investigator; Received none from Novartis for consultant & investigator; Received none from Pfizer for consultant & investigator; Received none from Celgene Corporation for consultant & investigator; Received none from Clinuvel for consultant & investigator; Received none from Eli Lilly & Co. for consultant & investigator; Received none from Janssen Ortho Biotech for consultant & investigator; Received none from LEO Pharmaceuticals for consultant & inves.

References

  1. Klaassen KM, van de Kerkhof PC, Pasch MC. Nail Psoriasis: a questionnaire-based survey. Br J Dermatol. 2013 Apr 1. [View Abstract]
  2. de Vries AC, Bogaards NA, Hooft L, Velema M, Pasch M, Lebwohl M, et al. Interventions for nail psoriasis. Cochrane Database Syst Rev. 2013 Jan 31. 1:CD007633. [View Abstract]
  3. Farber EM, Bright RD, Nall ML. Psoriasis. A questionnaire survey of 2,144 patients. Arch Dermatol. 1968 Sep. 98(3):248-59. [View Abstract]
  4. Langenbruch A, Radtke MA, Krensel M, Jacobi A, Reich K, Augustin M. Nail involvement as a predictor of concomitant psoriatic arthritis in patients with psoriasis. Br J Dermatol. 2014 Nov. 171(5):1123-8. [View Abstract]
  5. Balestri R, Rech G, Rossi E, Starace M, Malavolta N, Bardazzi F, et al. Natural history of isolated nail psoriasis and its role as a risk factor for the development of psoriatic arthritis: a single center cross sectional study. Br J Dermatol. 2016 Sep 2. [View Abstract]
  6. Choi JW, Kim BR, Seo E, Youn SW. Identification of nail features associated with psoriasis severity. J Dermatol. 2016 Sep 7. [View Abstract]
  7. Al-Mutairi N, Nour T, Al-Rqobah D. Onychomycosis in patients of nail psoriasis on biologic therapy: a randomized, prospective open label study comparing Etanercept, Infliximab and Adalimumab. Expert Opin Biol Ther. 2013 May. 13(5):625-9. [View Abstract]
  8. Kouskoukis CE, Scher RK, Ackerman AB. The "oil drop" sign of psoriatic nails. A clinical finding specific for psoriasis. Am J Dermatopathol. 1983 Jun. 5(3):259-62. [View Abstract]
  9. Handfield-Jones SE, Boyle J, Harman RR. Local PUVA treatment for nail psoriasis. Br J Dermatol. 1987 Feb. 116(2):280-1. [View Abstract]
  10. Fredriksson T. Topically applied fluorouracil in the treatment of psoriatic nails. Arch Dermatol. 1974 Nov. 110(5):735-6. [View Abstract]
  11. Feliciani C, Zampetti A, Forleo P, Cerritelli L, Amerio P, Proietto G, et al. Nail psoriasis: combined therapy with systemic cyclosporin and topical calcipotriol. J Cutan Med Surg. 2004 Mar-Apr. 8(2):122-5. [View Abstract]
  12. Yamamoto T, Katayama I, Nishioka K. Topical anthralin therapy for refractory nail psoriasis. J Dermatol. 1998 Apr. 25(4):231-3. [View Abstract]
  13. Bianchi L, Soda R, Diluvio L, Chimenti S. Tazarotene 0.1% gel for psoriasis of the fingernails and toenails: an open, prospective study. Br J Dermatol. 2003 Jul. 149(1):207-9. [View Abstract]
  14. Scher RK, Stiller M, Zhu YI. Tazarotene 0.1% gel in the treatment of fingernail psoriasis: a double-blind,randomized, vehicle-controlled study. Cutis. 2001 Nov. 68(5):355-8. [View Abstract]
  15. Cannavo SP, Guarneri F, Vaccaro M, Borgia F, Guarneri B. Treatment of psoriatic nails with topical cyclosporin: a prospective, randomized placebo-controlled study. Dermatology. 2003. 206(2):153-6. [View Abstract]
  16. South DA, Farber EM. Urea ointment in the nonsurgical avulsion of nail dystrophies--a reappraisal. Cutis. 1980 Jun. 25(6):609-12. [View Abstract]
  17. Maranda EL, Nguyen AH, Lim VM, Hafeez F, Jimenez JJ. Laser and light therapies for the treatment of nail psoriasis. J Eur Acad Dermatol Venereol. 2016 Aug. 30 (8):1278-84. [View Abstract]
  18. Rigopoulos D, Gregoriou S, Daniel Iii CR, et al. Treatment of nail psoriasis with a two-compound formulation of calcipotriol plus betamethasone dipropionate ointment. Dermatology. 2009. 218(4):338-41. [View Abstract]
  19. [Guideline] Elmets CA, Lim HW, Stoff B, et al. Joint American Academy of Dermatology-National Psoriasis Foundation guidelines of care for the management and treatment of psoriasis with phototherapy. J Am Acad Dermatol. 2019 Sep. 81 (3):775-804. [View Abstract]
  20. Tosti A, Ricotti C, Romanelli P, Cameli N, Piraccini BM. Evaluation of the efficacy of acitretin therapy for nail psoriasis. Arch Dermatol. 2009 Mar. 145(3):269-71. [View Abstract]
  21. Syuto T, Abe M, Ishibuchi H, Ishikawa O. Successful treatment of psoriatic nails with low-dose cyclosporine administration. Eur J Dermatol. 2007 May-Jun. 17(3):248-9. [View Abstract]
  22. Lawry M. Biological therapy and nail psoriasis. Dermatol Ther. 2007 Jan-Feb. 20(1):60-7. [View Abstract]
  23. Brown T. Fingernail Psoriasis Data Added to Humira Prescribing Info. Medscape News & Perspective. Available at http://www.medscape.com/viewarticle/877985?src=soc_fb_170405_mscpedt_news_pharm_humira. March 30, 2017; Accessed: April 6, 2017.
  24. [Guideline] Menter A, Strober BE, Kaplan DH, et al. Joint AAD-NPF guidelines of care for the management and treatment of psoriasis with biologics. J Am Acad Dermatol. 2019 Feb 13. [View Abstract]

Courtesy of Hon Pak, MD.

Classic distal interphalangeal joint involvement in psoriatic arthritis.

This patient has extensive psoriasis, nail involvement, and joint pain.

Anatomy of the nail, superior view.

Anatomy of the nail, sagittal view.

Classic distal interphalangeal joint involvement in psoriatic arthritis.

This patient has extensive psoriasis, nail involvement, and joint pain.

Anatomy of the nail, superior view.

Anatomy of the nail, sagittal view.

Courtesy of Hon Pak, MD.

Courtesy of Hon Pak, MD.

Courtesy of Hon Pak, MD.

Classic distal interphalangeal joint involvement in psoriatic arthritis.

This patient has extensive psoriasis, nail involvement, and joint pain.