Should we Add Trichotillomania to the List of Triggers for Erosive Pustular Dermatosis?

Broad Differential of Mimickers of EPDS

Erosive pustular dermatosis of the scalp is an inflammatory scalp condition that typically presents with erosion, crusts and pus. The lesions can progress to scarring alopecia.

The cause is not clear although a variety of “triggers” are known to be involved in triggering this condition including trauma, infections and medications.

EPDS can lead to scarring alopecia and therefore requires prompt attention and treatment.

Diagnosis requires a proper history and ruling out infection. A biopsy can sometimes help rule out mimicking conditions but is non specific.

Report of Erosive Scalp Lesions with Trichotillomania

I read with interest a report in the Journal of Cosmetic Dermatology of a possible newly reported association between trichotillomania and EPDS.

The patient was a 69 years old woman who presented with several eroded patches on the scalp. The erosions were increasing in number for three weeks and were noted to be painful and burning.

The patient had a past history of anxiety and major depression. She was taking daily escitalopram and paroxetine for the past 5 years. Six months prior to onset of the scalp lesions, her psychiatrist had noted the onset of psychotic symptoms and trichotillomania and had added aripiprazole to treatment.

The authors of this study noted several erosions with seropurulent exudate on the vertex area and mid-scalp. The eroded patches had different sizes ranging from 5 × 5 mm to 55 × 35 mm, and were covered by yellow-brown crusts at the margins. Swabs from the erosions were negative for bacteria and fungi.

Dermoscopy of unaffected areas revealed some features of trichotillomania. A biopsy was declined by the patient so that data is not available.

The authors reported in the paper that lesions were reported to have rapid resolution after treatment with oral prednisone (25 mg/day with progressive reduction) and a 0.05% clobetasol propionate cream (two applications daily).

Comments

This is interesting and highlights a number of important points for us all to consider about EPDS. First, EPDS has a very large number of mimickers and one needs to consider them all before making a diagnosis of EPDS.

First, EPDS has a great number of mimickers and one needs to make sure all have been considered. These include  

Squamous cell carcinoma

Basal cell carcinoma

Actinic keratoses

Tinea capitis and kerion

Blistering Diseases

Secondary Infection

Self Induced Excoriations

Discoid lupus

Dissecting Cellulitis

Folliculitis decalvans

Pustular drug reaction

Halogenoderma

Pyoderma gangrenosum

Pustular psoriasis

Subcorneal pustular dermatosis

Given the rapid response that the authors mention with prednisone and topical steroids, we know that some issues like skin cancer and tinea are not on the list. However, many mimickers can’t be ruled out in this case without a biopsy or without longer term follow up.

I’m not 100 % convinced this is a case of EPDS associated with trichotillomania but can’t exclude it. The scalp photos in this study could be in keeping with the typical excoriations we see in those with self induced excoriations that sometimes go along with trichotillomania.

Unfortunately, we don’t really know how long therapies were used in this study and we don’t have photos taken after everything healed and we don’t have long term follow up.

It’s helpful in EPDS to consider a biopsy and to consider direct immunofluorescence to rule out some autoimmune blistering issues including cicatricial pemphigoid. We also don’t know if the patient had other issues like eye or mouth involvement (that would support autoimmune blistering conditions). Swabs are important to rule out infection. EPDS typically responds rapidly to topical steroids which this patient did but a few conditions can respond to steroids. For this patient, we don’t know if the lesions recurred.

All in all this is an interesting paper which hopefully will trigger others to consider whether they accept a link between EPDS and TTM. That’s the wonderful thing about case reports - they get us all thinking and talking.

REFERENCE

Vaccaro et al. Erosive pustular dermatosis of the scalp as local complication of trichotillomania.J Cosmet Dermatol. 2022 Jan 8.