Practice Essentials
Erosive pustular dermatosis of the scalp (EPDS) is a chronic skin disease typically affecting elderly people, characterized by keratotic, erosive, and purulent plaques, which heal with scarring alopecia. Although most commonly presenting on the scalp, erosive pustulosis has also been observed on the extremities. Erosive pustulosis is most commonly observed in elderly patients following a history of extensive sun exposure. The condition generally progresses slowly over many years, although possible acute variants have been reported. [1] Previously described as a rare condition, increases in reporting have raised the likelihood that it is more common than previously thought. [2]
Signs and symptoms
Primary physical findings include the following:
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Yellow-brown keratotic crusts
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Superficial erosions
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Sterile nonfollicular pustules, although sometimes secondary infection is present
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Atrophy of affected skin with scarring alopecia
While erosive pustulosis is generally asymptomatic, patients may occasionally complain of pain, pruritus or burning at the site.
Diagnosis
Erosive pustulosis of the scalp is a clinical diagnosis. Biopsy may be required to rule out cutaneous carcinoma, neutrophilic dermatoses, or autoimmune bullous conditions. Biopsy results are nonspecific and may include parakeratotic and orthokeratosis, atrophy with loss of hair follicles, and a nonspecific and variable inflammatory infiltrate. Culture may be required to rule out secondary cutaneous infection.
Management
The historical mainstay of treatment for erosive pustulosis of the scalp has been high-potency topical steroids. Other treatments include topical tacrolimus, topical and oral retinoids, topical calcipotriol, topical dapsone, oral zinc sulfate, and oral cyclosporine, each with varying levels of success. In the authors' experience, debridement of the overlying crusts with a curette and electrocautery followed by daily application of petrolatum emollients or topical antibiotics, such as mupirocin 2% ointment, results in resolution over a series of treatments spaced at 2- to 3-week intervals.
For more information, see Treatment.
Background
Erosive pustulosis of the scalp was first described by Pye, Peachey, and Burton in 1979 as a rare disorder of uncertain etiology seen in elderly individuals. [3] Erosive pustulosis of the scalp is characterized by sterile pustules, erosions, and crusted lesions, as shown in the images below. [4] These lesions result in scarring alopecia of the involved areas. [5] Although its etiology remains unknown, erosive pustulosis of the scalp is seen in atrophied skin secondary to actinic damage or exposure to local trauma. Cases of erosive pustulosis of the scalp have been reported following trauma, surgery, skin grafting, thermal burn, laser, cryotherapy, sunburn, and topical chemotherapy, among others. [1, 5, 6, 7]
Cases of erosive pustulosis affecting the extremities have also been reported, [6, 8] as shown in the images below.
Erosive pustular dermatosis on the bilateral lower extremities in a woman with history of extensive UV exposure.
Pathophysiology
The etiology of erosive pustulosis of the scalp is poorly understood; however, several factors that may be related to the pathogenesis of the disease.
Cutaneous atrophy from any cause, but most commonly actinic damage, is a predisposing condition to erosive pustulosis of the scalp and seems to be present in almost all reported cases. [6]
Trauma and tissue damage may play a role in the development of erosive pustulosis of the scalp. Inflammatory triggers associated with erosive pustulosis include herpes zoster, iatrogenic insults of cryotherapy, topical chemotherapy (including topical ingenol mebutate 0.015% gel), [9] excisional surgery, skin grafting, [5, 6] hair transplantation, [10] thermal burn, [7] sunburn, [1] topical methyl aminolevulinate photodynamic therapy, [11] immunosenescence, [12] and carbon dioxide laser therapy. [13] A localized form of erosive pustulosis of the scalp has been reported after implantation of a cochlear implant. [14] A single case study reported the development of erosive pustular dermatosis of the scalp after contact dermatitis from a prosthetic hair piece. [15] There have also been two cases of erosive pustular dermatosis of the scalp occurring after treatment with topical 3.75% imiquimod for actinic keratoses of the scalp. [16] It is important to keep in mind that association should not be confused with causality. Although the above cited reports have described various medications, infections, surgical procedures, or topical agents occurring together with erosive pustulosis, it is unknown if they play a direct role in the pathogenesis of this condition.
Chronic inflammation is noted in histology studies, and it clearly plays a role in the persistence of erosive pustulosis of the scalp. [6]
Epidemiology
Frequency
Previously described as a rare condition, increases in reporting have raised the likelihood that erosive pustulosis of the scalp is more common than previously thought.
Race
Erosive pustulosis of the scalp is found more commonly in white persons. [17]
Sex
Erosive pustulosis of the scalp has a female predominance, with a female-to-male ratio of approximately 2:1. [6]
Age
Erosive pustulosis of the scalp primarily affects elderly persons, although cases have been reported in young patients following surgical excisions and burns. [6, 7, 18]
Prognosis
Erosive pustulosis of the scalp is a chronic condition. Erosive pustulosis of the scalp causes mild-to-moderate pruritus and pain. The appearance of the erosions and crusts are embarrassing to the patient, and the end result is scarring alopecia. Erosive pustulosis of the scalp is not a fatal condition.
Etiology
No specific cause of erosive pustulosis of the scalp has been identified, but actinic damage is a definite predisposing factor. Trauma, infection (herpes zoster), topical agents, surgical treatments, and various other inflammatory factors may trigger the condition.
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Yellow-brown crusts with atrophy on the vertex scalp.
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Yellow-brown crusts on the vertex scalp.
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A dense perifollicular infiltrate is composed of lymphocytes, neutrophils, histiocytes, and multinucleated giant cells (hematoxylin and eosin, 200x).
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Closer examination shows a predominantly neutrophilic infiltrate with a background of admixed lymphocytes and histiocytes (hematoxylin and eosin, 400x).
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Erosive pustular dermatosis on the bilateral lower extremities in a woman with history of extensive UV exposure.
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Crusts with underlying purulence on the lower extremity.
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Erosive pustulosis of the scalp prior to curettage.
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Erosive pustulosis of the scalp 4 weeks following two treatments of curettage debridement with electrodesiccation performed at 3-week intervals.
