Depigmented patches on forearms - Clinical Advisor

Depigmented patches on forearms

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  • Case #1

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    Case #1

  • Case #2

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    Case #2

Case #1

A man, aged 25 years, presents with patchy areas of depigmentation on his forearm, umbilicus, and groin. The centers of the lesions are hypopigmented, and the borders are hyperpigmented. The patient states that, initially, the lesions had been expanding but following that period, the lesions did not increase in size for several years. Upon further questioning, the patient admits to constipation and cold sensitivity. He also reported that he gained weight recently.

Case #2

A woman, aged 50 years, presents with a several-week history of a large erythematous patchy area of depigmentation with central scaling on her left forearm and scalp. She states that the rash is new. Upon further physical examination, the patient has no other rashes and has no oral or nasopharyngeal ulceration. She denies sensitivity to sunlight and has no history of renal dysfunction. Biopsy of one of the lesions reveals squamous cell carcinoma.

Case #1Vitiligo is an acquired autoimmune disease that typically affects young adults at approximately age 20 years, although it can appear earlier.1 It affects men and women equally and is found in 0.1% to 2% of the population.2 Patchy areas...

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Case #1

Vitiligo is an acquired autoimmune disease that typically affects young adults at approximately age 20 years, although it can appear earlier.1 It affects men and women equally and is found in 0.1% to 2% of the population.2 Patchy areas of depigmentation are commonly found on the fingers,  wrists, axillae, and groin;1 they may also affect the mucous membranes and hair.2 

Some individuals have a genetic predisposition to vitiligo.2,3 Several susceptibility genes have been implicated in the pathogenesis of vitiligo, including several human leukocyte antigen (HLA) types.2 Infection, stress, toxins, and trauma may also contribute to the development of the disease.2 Autoantibodies targeting melanocytes, resulting in their destruction, are frequently found in patients with vitiligo.2 Vitiligo is also associated with other autoimmune diseases, particularly autoimmune thyroid dysfunction such as Hashimoto and Grave disease, and patients should undergo additional screening to rule out these conditions.1 

This chronic progressive disease generally exhibits periods during which there is a pause in disease activity, interspersed with episodes during which further depigmentation occurs.1 A Wood lamp may be used to reveal larger areas of depigmentation correlating to activity of disease and can also be used to reveal areas of repigmentation.1 Repigmentation can occur spontaneously, although it is rare, seen in only 10% to 20% of cases.1,2 

There are several forms of classification of vitiligo, and the pattern of involvement may affect ease of diagnosis. Vitiligo may be divided into nonsegmental (type A) and segmental (type B).2 Segmental vitiligo affects specific dermatomes, which has led to speculation regarding involvement of the nervous system in this form of the disease.2 It may also be categorized as generalized, universal, segmental, and acrofacial.2 

Histopathologic findings in vitiligo include basal hypopigmentation and inflammation of the dermis, as well as absence of melanocytes and melanin from the epidermis, although in some rare cases melanocytes may still be present.3 Biopsy to confirm vitiligo is performed using immunohistochemical stains targeting melanocytes.3 Cytotoxic T-cell infiltrate and increased circulating cytokine levels are additional findings.2 

The differential diagnosis for vitiligo is extensive and includes postinflammatory hypopigmentation, tinea versicolor, piebaldism, nevus depigmentosus, discoid lupus erythematosus (DLE), and hypopigmented mycosis fungoides.2,3 In the case of tinea versicolor, lesions are mostly truncal and potassium hydroxide treatment reveals yeast.2 Lesions in piebaldism and nevus depigmentosus are usually noted at birth, unlike those of vitiligo, which develop over time.2 

There are several methods, beyond photographing the involved areas, to determine extent of involvement in a patient. To determine area of depigmentation and repigmentation, the Vitiligo Area Scoring Index may be used.1 Another useful system is the Vitiligo European Task Force tool, which takes into account both areas of depigmentation and repigmentation, as well as staging and spreading of the disease, but it has been found to be less consistent.1 

There are many treatment options available for vitiligo, although treatment very rarely results in complete repigmentation of the skin.1 The first-line treatment is topical steroids, such as fluticasone or clobetasol.1 This may be combined with ultraviolet (UV)-A light to improve repigmentation.1 The use of topical vitamin D analogues such as calcipotriol, in addition to psoralen plus UV light therapy, may be used to enhance initial repigmentation.1 Narrow-band UVB light may also have beneficial effects, especially if depigmentation is extensive or fails to respond to topical medication.1 Topical calcineurin inhibitors such as pimecrolimus are noted to improve repigmentation in some patients, and tacrolimus is especially helpful for central depigmentation (face and trunk).1 Systemic immunosuppressive regimens have been tried in the treatment of vitiligo, including oral corticosteroids or azathioprine, but are generally not recommended due to side effects.1 For adult patients, sunscreen and cosmetics are sometimes recommended rather than treatment.1 Topical self-tanning products can result in an increased quality of life but do not impact the course of the disease.1 Common side effects of medications used in the treatment of vitiligo include skin atrophy with the use of steroids and burning sensation with the use of topical calcineurin inhibitors, as well as photodamage with UV light treatment.1 Surgical management, especially split-skin grafting, may also be used in adults if the disease is not actively spreading.1 

Vitiligo causes significant reduction in quality of life and requires disease-specific treatment and psychologic therapy to elicit coping mechanisms.1 Further psychologic implications are severe and include anxiety, depression, and adjustment disorders; it is unclear whether these contribute to the pathogenesis of vitiligo or are consequences of the disease on mental health.2 Cognitive behavioral therapy has been shown, in several studies, to improve quality of life and coping,1 which can be valuable to patients (in addition to treatment of the skin disease itself).1 

The patient in our case was offered a biopsy, but given his classic clinical presentation of vitiligo, he declined. As the patient was bothered by the cosmetic appearance of the lesions, therapy with medium-potency topical corticosteroids was initiated. Thyroid studies revealed hypothyroidism, which was managed by another provider. At the 3-month follow-up visit, macules of repigmentation were noted. The patient was happy with the improvement and chose to continue therapy with topical corticosteroids.

Case #2

Discoid lupus erythematosus (DLE) is an autoimmune disease on the spectrum of lupus erythematosus but is limited to skin involvement. Only 5% of patients with DLE transition to systemic lupus erythematosus (SLE), with a higher risk of progression in DLE patients with generalized rather than localized disease.4,5 

DLE is the most common subtype of chronic cutaneous lupus erythematosus (CCLE).5 Women are affected more frequently than men, and the initial presentation usually occurs between age 40 years to 60 years.5 

Localized DLE generally affects patients above the neck and has a higher rate of remission, whereas generalized DLE may be present anywhere on the body but is especially common on extensor surfaces and has a much lower rate of remission.5,6 Initial lesions may present as erythematous macules that later appear as discoid scaly plaques with central hypopigmentation.5 Hair follicle involvement can occur and may lead to cicatricial alopecia.5 Complications of DLE include secondary development of squamous cell carcinoma within lesions or progression to SLE.5 

Genes and environmental cues are implicated in the development of lupus erythematosus.4 The exact mechanism of development of DLE is not completely understood, although molecular mimicry and autoantibodies are thought to play a role.6 Ultraviolet (UV) light is considered an inciting factor in the development of DLE and causes exacerbations of the chronic disease, so protection from the sun is necessary for patients with DLE.4 Additionally, DLE is often associated with generalized photosensitivity.6 

The differential diagnosis of DLE includes psoriasis, cutaneous T-cell lymphoma, sarcoidosis, and vitiligo.5 The distribution of generalized DLE on extensor surfaces5 may result in an incorrect diagnosis of psoriasis.5 The classic central hypopigmentation and peripheral hyperpigmentation may be mistaken for vitiligo, although the distribution of lesions of DLE differs. DLE may be distinguished not only based on clinical appearance, but also on biopsy.5,7 

The diagnosis of DLE requires clinical suspicion and biopsy; it is also critical to search for systemic signs such as ulcers or photosensitivity, which may indicate SLE.7 It is important to make this diagnosis early in order to reduce morbidity and mortality.4 If the diagnosis is suspected, patients should receive a thorough evaluation, including a complete blood count, measurement of antinuclear antibody levels, a urine sample, and possibly measurement of anti-double-stranded DNA and C3 and C4 levels.4 

Tissue biopsy results show basement membrane thickening on periodic acid-Schiff staining.4 A hematoxylin and eosin stain of the biopsy specimen shows basal cell liquefaction and vacuolar degeneration, inflammatory infiltrate, hyperkeratosis, and follicular plugging.4,5,7 Another common finding is dermoepidermal junction immune complex deposits, most frequently immunoglobulin G, via direct immunofluorescence.7 This is commonly known as the lupus band test and is useful in making a histopathologic diagnosis of DLE, but it may not be reflective in early cases.7 

In the management of DLE, earlier treatment leads to better results.4 Topical corticosteroids, such as clobetasol and triamcinolone, are used as first-line treatment of DLE but should be used cautiously in case of side effects.4 Chronic scarring lesions may benefit from intralesional steroid injections.4 Common side effects include striations of the skin with topical corticosteroids and atrophy with topical or intralesional steroids.4 Topical calcineurin inhibitors, such as tacrolimus, are another option, as are systemic retinoids.5,6 Antimalarial agents, such as hydroxychloroquine, are also used in the management of DLE, but they take several weeks to show any effect and carry the risk of retinal toxicity; therefore, patients should be under regular surveillance by an ophthalmologist.4,5 Thalidomide may be used if the DLE is unresponsive to steroids and antimalarial agents, but it is associated with birth defects if used during pregnancy.5 Other agents that may be used to treat resistant DLE include immunosuppressants such as methotrexate, mycophenolate mofetil, cyclosporine A, and azathioprine.5 Use of sunscreens and general avoidance of exposure to the sun is important to prevent worsening of lesions.5,6 

There is a significant psychologic effect on patients with DLE, as skin lesions may be large and may cause hair loss in affected areas.5 Disguising lesions with the use of makeup and/or wigs may be beneficial to patients.5 The presence of discoid lesions on the skin is detrimental to a patient’s mood and quality of life, and patients with DLE are found to have a lower perceived quality of life than patients with SLE.8 This psychologic aspect of the disease is important to keep in mind when diagnosing and managing DLE, in order to maximize patients’ quality of life and improve mood. 

For the patient in our case, two biopsies were performed, one of which revealed follicular plugging, vacuolar degeneration, and an interface inflammatory infiltrate. A diagnosis of DLE was made. Therapy with oral hydroxychloroquine and topical corticosteroids was initiated, and strict sun protection was advised. After one month of therapy, significant improvement was noted. The patient continued to show improvement at her 6-month follow-up.

Yasmin Qaseem, BS, BA, is a medical student and Maura Holcomb, MD, is a dermatology resident at Baylor College of Medicine in Houston.

References

  1. Gawkrodger DJ, Ormerod AD, Shaw L, et al. Guideline for the diagnosis and management of vitiligo. Br J Dermatol. 2008;159(5):1051-1076.
  2. Yaghoobi R, Omidian M, Bagherani N. Vitiligo: a review of the published work. J Dermatol. 2001;38(5):419-431.
  3. Kim YC, Kim YJ, Kang HY, et al. Histopathologic features in vitiligo. Am Dermatopathol. 2008;30(2):112-116.
  4. Panjwani S. Early diagnosis and treatment of discoid lupus erythematosus. J Am Board Fam Med. 2009;22(2):206-213. 
  5. Okon LG, Werth VP. Cutaneous lupus erythematosus: diagnosis and treatment. Best Pract Res Clin Rheumatol. 2013;27(3):391-404.
  6. Farley-Loftus R, Mahlberg M, Merola JF, et al. Generalized discoid lupus erythematosus. Dermatol Online J. 2009;15(8):18. 
  7. Naqqash S, Asad F, Pal SS. Direct immunofluorescence and histopathology in chronic discoid lupus erythematosus. Journal of Pakistan Association of Dermatologists. 2011;21:98-101. 
  8. Martins PR, Skare T, Ferrari TA, et al. Comparative analysis of the quality of life of patients with discoid lupus erythematosus and systemic lupus erythematosus with skin injuries. An Bras Dermatol. 2012;87(2):326-328. 
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