Dermatology Online Journal

Severe retention hyperkeratosis occurring with Susac syndrome
KaLynne Harris MD, Lana N Pho MD, Anneli R Bowen MD
Dermatology Online Journal 16 (10): 8

University of Utah

---

Abstract

A 50-year-old woman presented for asymptomatic yellow hyperkeratotic plaques limited to her face. The plaques reportedly arose over the six months prior to her clinic visit. She was healthy prior to the diagnosis of Susac syndrome (retinocochleocerebral vasculopathy) two years before. A punch biopsy was performed and revealed retention hyperkeratosis. Retention hyperkeratosis is a benign and commonly seen skin condition in primary care and dermatology. Retention hyperkeratosis occurs when there is abnormality of routine desquamation that can be associated with poor hygeine. Our case of retention hyperkeratosis is unique because of the profound presentation in a setting of a poorly treated psychiatric condition. Treatment consisted of daily topical exfoliative care.

---

Case report

A 50-year-old woman who was accompanied by her husband presented to us for evaluation of asymptomatic yellow hyperkeratotic plaques on her face, sparing her periorbital and perioral regions. The patient did not recall any inciting events or exacerbating factors, and did not appear to have insight into her diagnosis of Susac syndrome two years previously. Her current medications included L-methylfolate, lorazepam, and alprazolam for anxiety. Review of systems was remarkable for a 50-pound weight loss and fear of touching of her face since the diagnosis of Susac syndrome.

Figure 1	Figure 2
Figures 1 and 2. Initial presentation to our clinic for yellow plaques on forehead and lower face, respectively.

Exam revealed yellow hyperkeratotic papules coalescing into larger, well-demarcated plaques on the face but sparing the periorbital and perioral regions (Figures 1 and 2). No lymphadenopathy was noted.

Figure 3	Figure 4
Figure 3. Histology of affected skin with 4 mm punch. Figure 4. PAS stain of stratum corneum from affected skin showing multiple fungal elements.

A 4 mm punch biopsy was performed (Figure 3). Histopathology shows exuberant orthokeratosis of the stratum corneum containing abundant fungal elements and bacteria. There is no significant dermal or epidermal inflammation. These findings are consistent with retention hyperkeratosis with secondary pityrosporum and bacterial colonizations (Figure 4). Tissue culture did not support invasive infection.

Treatment and follow-up

Figure 5	Figure 6
Figures 5 and 6. Improvement in retention hyperkeratosis after one month of treatment with exfoliative wash, chlorhexadine, and ketoconazole shampoo on forehead and lower face, respectively.

We treated the patient with daily exfoliative washes using chlorhexadine and ketoconazole shampoo. The scrubs were performed by her sister because the patient refused to touch her face. Improvement was seen at one-month follow up (Figures 5 and 6).

Discussion

Susac syndrome is a rare autoimmune endotheliopathy affecting primarily young women. It classically presents with the clinical triad of encephalopathy, branch retinal artery occlusions, and hearing loss and exhibits distinctive MRI findings [1]. The complete triad is not always present at diagnosis [2]. Susac syndrome often includes psychiatric illness, commonly paranoia [1, 3]. It is thought to have a similar pathology to dermatomyositis with autoimmune endotheliopathy affecting skin and muscle in dermatomyositis and neural tissue in Susac syndrome [4, 5]. Treatments for Susac syndrome and dermatomyositis are similar, including high dose corticosteroids, intravenous immunoglobulin, steroid-sparing immunosuppressants, and rituximab [3, 4, 5].

To our knowledge, there are no previous reports of skin disease in Susac syndrome. In this case, the retention hyperkeratosis was not a primary cutaneous manifestation, but a secondary phenomenon relating to paranoia as part of Susac syndrome.

Retention hyperkeratosis is commonly recognized by dermatologists but rarely reported. Keratinocytes form a stratified squamous epithelium in the skin [6]. Keratinocytes proceed through orderly differentiation from the basal layer to the cornified layer. The cornified layer, made up of terminally differentiated keratinocytes, called corneocytes, provides a barrier between the body and the outside world that keeps water and other molecules in and external entities, including microbes, out [6]. As part of normal skin growth, corneocytes are shed in an orderly manner [6, 7]. The process by which corneocytes are shed is not completely understood but likely is dependent on weakening of intercorneocyte junctions, called corneosomes, by both enzymatic and mechanical forces [7]. Our patient developed retention hyperkeratosis caused by dysfunctional corneocyte shedding. We cannot know the exact mechanism, but lack of mechanical friction secondary to her fear of touching her face may be a factor. This hypothesis is supported by the lack of hyperkeratosis on other parts of her body, which she did not fear touching, and her improvement with exfoliating wash. Typically, retention hyperkeratosis is a mild, benign skin disorder. Our case represents a rare extreme manifestation related to inadequately treated psychiatric illness.

References

1. Susac JO, Egan RA, Rennebohm RM, et al. Susac’s syndrome: 1975-1005 microangiopathy/autoimmune endotheliopathy. J Neurol Sci. 2007;257:270-272. [PubMed]

2. Aubart-Cohen F, Klein I, Alexandra JF, et al. Long-term outcome in Susac syndrome. Medicine. 2007;86:83-102. [PubMed]

3. Rennebohm RM, Egan RA, et Susac JO. Treatment of Susac’s Syndrome. Curr Treat Options Neurol. 2008;10:67-74. [PubMed]

4. Rennebohm RM, Lubow M, Rustin J, et al. Aggressive immunosuppressive treatment of Susac’s syndrome in an adolescent: using treatment of dermatomyositis as a model. Pediatr Rheumatol Online J. 2008;6:3. [PubMed]

5. Rennebohm RM et Susac JO. Treatment of Susac’s syndrome. J Neurol. Sci. 2007;257:215-220. [PubMed]

6. Bolognia JL, Jorizzo JL, et Rapini RP, eds. Dermatology 2nd edition. Elsevier Limited; 2008. ISBN: 978-1-4160-2999-1

7. Pierard GE, Goffin V, Hermanns-Le T, et al. Corneocyte desquamation. Int J of Mol Med. 2000;6:217-221. [PubMed]

© 2010 Dermatology Online Journal