AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Background

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. 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.

The Medscape Psoriasis Resource Center may be of interest.

Pathophysiology

The pathogenesis of the psoriatic nail disorder is not completely known. It 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 process is being investigated as part of the pathogenesis of psoriasis.

Frequency

United States

Psoriatic nail disease occurs in 10-55% of all patients with psoriasis. 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. 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,¹ 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 increases 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).

International

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

Mortality/Morbidity

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

Sex

Both sexes are affected equally.

Age

The prevalence increases with the age of the population studied.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

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.

Physical

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. 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.

• Below is a summary of the clinical signs of nail psoriasis and the portion of the nail unit that is affected followed by a definition.
• • Oil drop or salmon patch/nail bed²: 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.
  • Pitting/proximal nail matrix: Pitting is a result of the loss of parakeratotic cells from the surface of the nail plate.
  • Beau lines/proximal nail matrix: These lines are transverse lines in the nails due to intermittent inflammation causing growth arrest lines.
  • Leukonychia/midmatrix disease: Leukonychia is areas of white nail plate due to foci of parakeratosis within the body of the nail plate.
  • Subungual hyperkeratosis/hyponychium: Subungual hyperkeratosis affects the nail bed and the hyponychium. Excessive proliferation of the nail bed can lead to onycholysis.
  • Onycholysis/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 bed or nail matrix: 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.
  • Psoriatic arthritis with nail changes/phalanx
• Psoriatic nail disease can also occur with onychomycosis and paronychia.
• Most people with psoriatic arthritis have nail changes that can be classified as follows:
• • Type I - Classic distal interphalangeal joint involvement (5% of patients)
  • Type II - Arthritis mutilans
  • Type III - Symmetric polyarthritis
  • Type IV - Asymmetric oligoarthritis (the most common type of psoriatic arthritis, occurring in 70% of patients)
  • Type V - Ankylosing spondylitis

Causes

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.

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Other Problems to be Considered

Idiopathic trachyonychia
Punctate keratoderma

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Procedures

• 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.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Medical Care

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. No curative treatment exists at the present time. Onychomycosis (if present) requires antifungal therapy for improvement. The treatment options for nail psoriasis include topical corticosteroids, intralesional corticosteroids, psoralen plus ultraviolet light A (PUVA),³ topical fluorouracil,⁴ topical calcipotriol,⁵ topical anthralin,⁶ topical tazarotene,^{7, 8} topical cyclosporin,⁹ avulsion therapy,¹⁰ and systemic therapy for severe cases. For preventive care, keep the nails dry and protect them from trauma to avoid the Koebner effect. In areas of onycholysis, the nail plate should be trimmed to the point of separation for medications to be effective.

• 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). 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. A topical preparation of a combination of high-potency corticosteroid and calcipotriol may benefit some patients.
• 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.
• 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 have been used in patients with severe cutaneous psoriasis. Few studies have shown significant improvement in nail psoriasis with long-term results. At present, 3 systemic medications are most commonly used for psoriasis and nail psoriasis: methotrexate, retinoids, and cyclosporin. All 3 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.
• Avulsion therapy with 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.
• 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.

Surgical Care

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.

Activity

Avoiding trauma to the nail, which prevents onycholysis and possible secondary microbial colonization in the nail, is important. Patients should keep psoriatic nails clean and dry.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

The goals of pharmacotherapy are to reduce morbidity and to prevent complications.

Drug Category: Corticosteroids

These agents have anti-inflammatory properties and cause profound and varied metabolic effects. In addition, these agents modify the body's immune response to diverse stimuli.

Drug Category: Psoralens

These agents are very effective for cutaneous psoriasis and can improve nail psoriasis. They may improve nail psoriasis in 3-6 months.

Drug Category: Antimetabolites

These agents inhibit cell growth and proliferation.

Drug Category: Keratolytics

These agents cause cornified epithelium to swell, soften, macerate, and then desquamate.

Drug Category: Retinoids

These agents decrease the cohesiveness of abnormal hyperproliferative keratinocytes and may reduce the potential for malignant degeneration. They modulate keratinocyte differentiation. They have been shown to reduce the risk of skin cancer formation in patients who have undergone renal transplantation.

Drug Category: Immunosuppressives

These agents inhibit key factors of the immune system.

Drug Category: Vitamins

These agents are essential for normal DNA synthesis and cell function.

Drug Category: Topical Skin Product

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Deterrence/Prevention

• For preventive care, keep the nails dry and protect them from trauma to avoid the Koebner effect.

Complications

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

Patient Education

• For excellent patient education resources, visit eMedicine's Psoriasis Center and Arthritis Center. Also, see eMedicine's patient education articles Nail Psoriasis, Psoriasis, Types of Psoriasis, Understanding Psoriasis Medications, and Psoriatic Arthritis.

MULTIMEDIA

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

Media file 1:  Anatomy of the nail, superior view.
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Media file 2:  Anatomy of the nail, sagittal view.
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Media file 3:  Courtesy of Hon Pak, MD.
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Media file 4:  Courtesy of Hon Pak, MD.
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Media file 5:  Courtesy of Hon Pak, MD.
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Media file 6:  Classic distal interphalangeal joint involvement in psoriatic arthritis.
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Media file 7:  This patient has extensive psoriasis, nail involvement, and joint pain.
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REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Multimedia
• References

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25. Tosti A, Piraccini BM, Cameli N, Kokely F, Plozzer C, Cannata GE, et al. Calcipotriol ointment in nail psoriasis: a controlled double-blind comparison with betamethasone dipropionate and salicylic acid. Br J Dermatol. Oct 1998;139(4):655-9. [Medline].
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Article Last Updated: Nov 8, 2007