Saturday, January 19, 2019

Retroauricular Dermatitis: An Orphan Disease

The patient is an 11 year-old girl with a one-year history of a dermatitis in the right retroauricular sulcus.  She has a history of  an eczematous  eruption on her thighs. She was prescribed mupirocin and betamethasone valerate ointmens.  They both caused burning and pruritus and she refused to use them.  There is a history of a vaginal dermatitis a year or so ago, which was successfully treated with topical corticosteroids.

O/E:  There is erythema, crusting and mild fissuring in the above-mentioned area.  The left retorauricular area is mildly affected.  Presently there are no findings of atopic dermatitis in the usual areas.

Clinical Image:

Lab:  Wound culture was positive for 3+ Staph aureus and 3+ Group B Strep.

Diagnosis:  Retroauricular dermatitis.

We prescribed cephalexin 250 mg q.i.d. and a small amount of Vaseline for the dryness and fissuring.  Patch testing will be recommended if there are further symptoms suggestive of contact dermatitis.

Comments:  Retroauricular dermatitis, also called "infra-auricular fissures," appears to be an under-reported entity.  Although it is common in atopic dermatitis, there have been few articles about it. I see a few cases a year and the vast majority yield coagulase positive Staph aureus and occasionally strep when cultured. Most respond quickly to mupirocin ointment and a  low to moderate strength topical steroid.  This patient’s symptoms make her an outlier.  In addition, she has no findings of atopic dermatitis at this time.
Do any of you have thoughts on this entity?  The take home message here is that, as with atopic dermatitis, these lesions are frequently colonized with Staph aureus.

1. Infra-auricular fissures in atopic dermatitis.
Tada J, et. al. Acta Derm Venereol. 1994 Mar;74(2):129-31.
Abstract: Retro-auricular or auricular dermatitis in atopic dermatitis (AD) is common and important for the diagnosis of AD in infancy and even in adulthood. Particularly, "infra-auricular fissures", acute eczematous changes like fissures at the adhesive junction of ear lobes, seem to be prominent features for the diagnosis of AD. Of 137 patients with AD, 81.8% showed present or past existence of infra-auricular fissures, but only one of the 30 controls. Of the 46 patients with severe AD, 98% had infra-auricular fissures, compared to 74% in those with moderate and mild AD. Our findings suggest that infra-auricular fissures are important for the diagnosis of AD and should be cited in a list of criteria for the diagnosis of AD.

2. Streptococcal perianal disease in children. Kokx NP, Comstock JA, Facklam RR.  Pediatrics. 1987 Nov;80(5):659-63.  PubMed Link.

3. Psoriasis inversa: A separate identity or a variant of psoriasis vulgaris?
Omland SH, Gniadecki R. Clin Dermatol. 2015 Jul-Aug;33(4):456-61.
Abstract: Psoriasis is a chronic skin disorder affecting approximately 2% of the European and American population. The most common form of psoriasis is the chronic plaque type. Inverse psoriasis, also named flexural or intertriginous psoriasis, is not considered a separate disease entity but rather a special site of involvement of plaque psoriasis, characterized by its localization to inverse/intertriginous/flexural body sites. We review current evidence and establish whether inverse psoriasis is a separate disease entity based on characteristics in terms of epidemiology, pathogenesis, clinical and histologic presentation, microbiology, and treatment.


  1. From Khalifa Sharquie, Baghdad, Irag: This is classical picture of retroauricular psoriasis that is commonly seen in children as the first manifestation of psoriasis

  2. From Rpbert Shapiro, Hilo, Hawaii: Clinically it looks like crusted eczema, c/w seb derm. I would say it’s more colonized than impetiginized. Unlikely to be primary contact in that location. Secondary contact to what she’s applying is possible. She looks to have a very low density of scalp hair (clinically alopecic). She might need screening labs for causes of hair loss in 11 year old and hair prep to check for Netherton’s in which case TIM’s would be theoretically contra-indicated, although systemically pimecrolimus has no immunosuppressive effect, but tacrolimus obviously does.

  3. From Krystal Jonnes: feeling more psoriasiform than atopic disease to me. I think in kids it is hard to tell the difference as there is a lot of overlap, and they tend to declare themselves later into adolescence. This would fit better w the vaginal dermatitis too, as I wouldn’t expect that to be eczema unless it was a contact derm. Strep can be an exacerbator of psoriasis, as you know, too. I would look for perianal erythema as that can be a clue... and watch her over time... but wouldn’t be surprised if it had more of a psoriasis flare in her teenage years..

  4. from Brian Maurer, Pediatric practitioner, Connecticut:
    I do see a fair number of kids with retroauricular dermatitis, mostly as part of a presentation of infantile eczema. In babies it usually responds to a mild steroid cream; although many times we do see colonization with staphylococcus. Some clinicians feel that staph may actually exacerbate the eczema; treating the staph with a course of oral cephalexin usually improves the eczema flare.

  5. From Rick Sontheimer: As I have always worked in USA academic medical centers that have had one or more pediatric dermatology faculty, I do not see children younger than 10 years of age in my dermatology outpatient practice. The one exception is younger children having clinical issues/questions relating to autoimmune connective tissue diseases. However, I do have seven grandchildren, some of whom are atopic. And they are frequently turning up with dermatitic rashes that are often found to be the result of an irritant or allergic contact dermatitis. In addition, I do see a lot of allergic contact dermatitis in my adolescent and adult dermatology practices.

    First, I feel that this pediatric patient sounds like she is atopic having a history of eczematous rash on thighs, steroid-responsive vaginal dermatitis, post- and infra-auricular fissures (which in themselves are strong risk factor for atopic dermatitis) and staph impetiginization of the retroauricular dermatitic skin changes.

    My first thoughts in this case would be an occult allergic contact dermatitis superimposed on an atopic diathesis. Modern studies have shown that allergic contact dermatitis is more common in children with atopic dermatitis than has traditionally been thought to be the case. If the patient had previously used mupirocin ointment and the betamethasone ointment for the thigh dermatitis and/or vaginal dermatitis, she may have become sensitized to one or more of the chemicals in those ingredients including the mupirocin and topical steroid molecule itself.

    Because of the complexity of contact allergens (~4000 chemicals known to be contact sensitizers), I consider this to be the black hole/black universe of dermatologic disorders. Compounding this is the fact that many of the patients that I see these days cannot afford to undergo formal patch testing because of not having medical insurance or having exorbitantly-high annual medical insurance deductibles (5,000-$7,000 for a young family). Thus, like Luke Skywalker, I'm frequently required to "use the Force" when trying to sort among the various candidate offenders in this dark universe.

    If the patient had previously been using mupirocin ointment and/or betamethasone ointment for her earlier eczematous thigh and vaginal dermatitic changes, perhaps she became sensitized to one or more chemicals in those products. This could account for the patient’s acute symptoms when using these products on the impetiginized retroauricular eruption. Mupirocin has been documented to be a contact sensitizer. In addition, corticosteroid molecules when applied topically can be contact sensitizers. Also, topical sensitizers are often present in inexpensive OTC nail care cosmetics that could be spread to the retroauricular areas by rubbing or scratching. (I learned this from my 11-year-old atopic granddaughter.)

    Also, does this patient wear eyeglasses or sunglasses intermittently? There are potential contact sensitizers in the plastic, metal and protective coatings used in making eyeglasses. And if she does wear glasses, does she have the nervous habit of sometimes chewing on the temple plastic end pieces that secure the glasses to the ears? That habit could make sensitizing chemicals in the eyeglasses more likely to penetrate the skin. If so, this could explain the asymmetry of the reticular retroauricular dermatitis in this patient.

    And, like my 11-year-old granddaughter, has the patient starting using various personal care products in addition to nail polish that can contain contact sensitizers (eg, fragrant wash-off hair care products containing potent preservative allergens like methylisothiazolinone)? And, has she previously had her ears pierced?

    Before accepting the diagnosis of an impetiginized retroauricular dermatitic manifestation of atopic dermatitis, I personally would want to address the possibility of an occult allergic contact dermatitis, especially if this patient’s retroauricular inflammatory skin changes prove to be a recurring problem.

  6. We must not be satisfied with retroauricular dermatitis as a diagnosis as it is just a description of the distribution of lesions, an important step in dermatological diagnosis but still incomplete.
    It is the distribution, often with fissures in seborrheic dermatitis, more often in infantile seborrheic dermatitis as mentioned by Brian Maura. Bacteria grown in the culture are unsurprising as staph aureus is normal commensal which will multiply at the fissure. Yeast like Candida will also cause fissure behind the ears.
    This child is probably prone to yeast infection which may have accounted for her ‘vaginal dermatitis’ earlier on.
    May I suggest a good treatment of ketoconazole shampoo, sebclair cream to scalp, behind ears, nadilabial folds and eyebrows. Fusidic acid cream is my secret recipes for bad fissures, especially in this case with staph aureus hitching a ride. Well, please let me know if it works for your patients too?


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