A man in his 30s was referred for acute onset of pruritic scaly eruptions of the groin, penis, scrotum, and pubic mound. The lesions started to appear 3 weeks prior to presentation with an oval erythematous lesion located around the left thigh. About 7 days after the appearance of the first lesion, others began to appear. The patient reported that 2 weeks before the appearance of the first lesion, he had been inoculated against yellow fever and had an episode of coryza and hacking cough.
The lesions consisted of multiple, coalescent oval plaques of 0.2 cm to 4 cm in longest diameter (Figure) with atypical scales. Other skin areas and mucosal surfaces were unaffected. The findings of general and systemic examinations were normal. Skin scrapings for potassium hydroxide examination, complete blood cell counts, urinalysis, blood glucose assay, VDRL (Venereal Disease Research Laboratory) test, and human immunodeficiency virus antibodies were all normal. The pruritus and eruptions cleared within 6 weeks following treatment with mometasone furoate cream and oral Levocetirizine, 5 mg/d, leaving postinflammatory hyperpigmentation.
Skin lesions present on the groin, genitals, and pubic mound show multiple oval, sharply defined, coalescent, scaly, annular plaques surrounded by erythema.
Pityriasis Rosea (PR) is a self-limiting papulosquamous disorder typically characterized by sudden onset of a larger scaly plaque (herald patch) followed (about 1-2 weeks later) by eruptions of multiple, bilateral, smaller, scaly oval or round lesions that follow the Langer lines of cleavage on the trunk and proximal parts of extremities. Skin lesions usually last about 6 weeks. Current evidence indicates that PR is a type of viral exanthema and the cause may be linked to human herpes virus (HHV)-6 and HHV-7.1
Approximately 20% of patients present with atypical or variant forms of PR, which are less readily recognized than typical eruptions and may pose a diagnostic challenge.2,3 The morphologic characteristics of the eruption may be papular, vesicular, purpuric or hemorrhagic, or urticarial. Very small lesions will be observed in papular PR, and PR with enormous plaques is known as pityriasis rosea gigantea of Darier. A morphologic variant characterized by atypical large patches that tend to be few in number and coalescent has been described. In this variant, commonly referred to as pityriasis circinata et marginata of Vidal or limb-girdle PR, the eruption generally appears in the axillae, the groin, or both, with the trunk and extremities usually spared.4,5 A simple classification for atypical pityriasis rosea has been proposed by Chuh and Zawar (Box).6
A patient is diagnosed as having pityriasis rosea if:
On at least one occasion or clinical encounter, he/she has all the essential clinical features and at least one of the optional clinical features, and
On all occasions or clinical encounters related to the eruption, he/she does not have any of the exclusional clinical features.
The essential clinical features are:
Discrete circular or oval lesions,
Scaling on most lesions, and
Peripheral collarette scaling with central clearance on at least two lesions.
The optional clinical features are:
Truncal and proximal limb distribution, with less than 10% of lesions distal to mid-upper-arm and mid-thigh,
Orientation of most lesions along skin cleavage lines, and
A herald patch (not necessarily the largest) appearing at least two days before eruption of other lesions, noted from patient history or from clinical observation.
The exclusional clinical features are:
Multiple small vesicles at the center of 2 or more lesions,
Two or more lesions on palmar or plantar skin surfaces, and
Clinical or serologic evidence of secondary syphilis.
This outline was first published by Chuh and Zawar6 and is reproduced here with permission.
In our patient, the eruption fulfills all 3 essential clinical features (discrete annular lesions, scaling, and peripheral collarette scaling with central clearance on at least 2 lesions), all 3 optional clinical features (relative truncal distribution, orientation along skin cleavage lines, and herald patch), and none of the exclusional clinical features. This case has clinical features of localized PR, papular PR, and pityriasis circinata et marginata of Vidal. It should also be noted that the involvement of penile and scrotal skin is rarely reported in PR. Physicians should be aware of the wide spectrum of PR variants so that appropriate management and reassurance can be offered.
Corresponding Author: Piotr Brzezinski, MD, PhD, Department of Dermatology, Sixth Military Support Unit, os Ledowo 1N, 76-270 Ustka, Poland (firstname.lastname@example.org).
Published Online: July 30, 2014. doi:10.1001/jamadermatol.2013.10505.
Conflict of Interest Disclosures: None reported.
Brzezinski P, Chiriac A. Uncommon Presentation of Pityriasis Rosea After Yellow Fever Inoculation. JAMA Dermatol. 2014;150(9):1020-1021. doi:10.1001/jamadermatol.2013.10505