Pityriasis versicolor atrophicans

ARTICLE

ejd.2012.1661

Auteur(s) : Óscar Tellechea oetellechea@gmail.com, Mariana Cravo, Ana Brinca, Margarida Robalo-Cordeiro

Clínica de Dermatologia Hospital da Universidade de Coimbra 3000-075 Coimbra Portugal

A 35-year-old male presented with atrophic skin lesions on the back, first noticed 2 months before. Observation showed asymptomatic, erythematous, slightly atrophic, well circumscribed small patches, displaying occasional linear or vermiculated disposition on the middle third of the back (figure 1A). Some lesions contained minute surface telangiectasias (figure 1B). General physical examination was normal. No previous treatment had been instituted. Routine blood tests (whole blood counts, blood chemistry) as well as VIH1 and VIH2, Hepatitis B and C serologies, ANAs, VDRL, Serum Angiotensin Converting Enzyme, serum lisozyme and chest X ray were normal or negative.

The histological examination of one lesion disclosed capillary ectasia in the upper dermis, surrounded by a mild lymphomononucleated inflammatory infiltrate, flattening of rete ridges (figure 1E) and, clearly, PAS positive branching septate hyphae and spores within the stratum corneum (figure 1F), featuring the classic «spaghetti and meatballs» aspect, characteristic of pityriasis versicolor (PV). Verhoeff stain showed no alterations in the elastic tissue. The diagnosis of PV atrophicans was then established and the patient was treated with itraconazole (100 mg/day, 6 weeks) with subsequent resolution of telangiectasia and major improvement of the atrophy and erythema (figures 1C-D).

PV atrophicans is an exceptional form of PV [1, 2]. Due to the misleading aspect of the elementary lesion, the clinical impression is habitually acne scars or anetoderma/macular atrophy, as in our case. This may prompt unnecessary investigation of the multiple causes of secondary macular atrophy.

It is the histological examination that enables the diagnostic [1]. In fact, although the mycologic study remains important for diagnosis of PV atrophicans [2], it implies that PV is suspected clinically, which is seldom the case. Additionally, mycological evidence of Malassezia on the skin cannot always be equated to PV [3]. In contrast, histological demonstration of short branching septate hyphae and spores within the stratum corneum is characteristic of PV, but not a feature of normal skin, nor of primary or secondary macular atrophy [4].

PV atrophicans should not be confused with PV pseudoatrophicans [5, 6]. In the latter, atrophy is iatrogenic and secondary to prolonged topical corticotherapy. In contrast with PV atrophicans, in PV pseudoatrophicans the more typical hypo- and hyperpigmentated PV lesions coexist with the atrophic patches and clinical resolution requires the suspension of the dermocorticoids.

Although the topography of PV atrophicans generally follows that of common PV, the face or arm can be exclusively affected [1], or, as in our case, the middle of the back.

Concerning prognosis, partial or complete resolution can be expected after appropriate antifungal therapy. This further argues against the possibility that PV atrophicans could merely represent anetoderma with incidental Malassezia colonization.

The atrophic and telangiectactic character of PV atrophicans remain obscure. Capillary ectasia could be related to the direct angiogenic role of the yeast, or via induction of a Th1 hypersensitivity response to fungal antigens, with release of IFN-γ and IL-1 [1, 2, 5]. The intensity and the strictly perivascular disposition of the inflammatory infiltrate, as well as the absence of eosinophils, as found in our case, would argue in favour of the latter hypothesis. The atrophy is most probably related to the flattening of rete ridges, demonstrable in most cases (figure C), dependent on similar mechanisms [1]. Contrasting to anetoderma, elastic tissue alterations seem irrelevant to the atrophy in PV atrophicans, as they were not found in any case, including the present one.

In conclusion, PV atrophicans is an exceptional and clinically misleading form of PV that should be included in the differential diagnosis of macular atrophy/anetoderma Histology is diagnostic and adequate treatment enables the improvement or even the cure of this curious eruption.

Disclosure

Financial support: none. Conflict of interest: none

References

1. Crowson AN, Magro CM. Atrophying tinea versicolor: a clinical and histological study of 12 patients. Int J Dermatol 2003; 42:928-32.

2. Romano C, Maritati E, Ghilardi A, Miracco C, Mancianti F. SA case of pityriasis versicolor atrophicans. Mycoses 2005; 48:439-41.

3. Ashbee HR, Evans EG. Immunology of diseases associated with Malassezia species. Clin Microbiol Reviews 2002 ;15: 21-57.

4. Ackerman AB. Histologic diagnosis of inflammatory skin diseases. Baltimore. Williams and Wilkins, 1997.

5. Wagner G, Lubach D.Z. Pityriasis versicolor pseudoatrophicans. Hautkr 1987; 62: 321-24.

6. Mazuecos Blanca J, García-Bravo B, Moreno Giménez JC, Sotillo I, Camacho F. Pityriasis versicolor pseudoatrofica Med Cutan Ibero Lat Am 1990; 18:101-03.