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Photo Quiz

What Is This Patient’s Painful Rash?

Volume 61 - Issue 3 - March 2021

  • Answer: Atypical Pityriasis Rosea

    Pityriasis rosea (PR) is a self-limiting skin condition that presents as discrete scaly papules and plaques located along the trunk and limbs.1 The diagnosis of PR in its classical form is made clinically, but variants do exist.

    Atypical forms of PR are relatively common, presenting in approximately 20% of patients. The variants are diverse in their symptoms, morphology, and location of lesions.2 Pityriasis circinata et marginata presents in adults with few large lesions in a limb-girdle distribution. Inversus PR has skin findings in the flexural areas, face, and neck. The PR of the extremities variant has squamous plaques that are confined to the extremities. Papular PR presents as small papular lesions on the proximal extremities.3 

    Skin biopsy will yield focal parakeratosis with or without acanthosis, spongiosis, or a perivascular infiltrate of lymphocytes and histiocytes, and occasionally extravasation of red cells.4

    Treatment is aimed at controlling symptoms and consists of corticosteroids or antihistamines. In some cases, acyclovir can be used to treat symptoms and reduce the length of disease. For severe cases, ultraviolet phototherapy can be considered.1

    DIFFERENTIAL DIAGNOSIS

    The rash associated with secondary syphilis may present with macular, maculopapular, or even pustular lesions. The rash of secondary syphilis usually begins on the trunk and proximal extremities and may involve all skin surfaces, including the palms and soles. Secondary syphilis also may be associated with fever, malaise, generalized lymphadenopathy, arthralgias, weight loss, and other constitutional symptoms.5

    Tinea corporis is a fungal infection of the face, trunk, or extremities that presents with red, annular, scaly, pruritic patches and plaques with raised scaly borders that expand peripherally with central clearing.6 The lesions may be single or multiple, with the size usually ranging from 1 to 5 cm; however, larger lesions and confluence of lesions also may be present.6

    Nummular eczema typically presents as a coin-shaped (nummular) red plaques on the skin that may be pruritic. The scale is thin and sparse. Lesions tend to not increase in size, although they may become more numerous. The dorsal hand is most commonly involved.7

    Guttate psoriasis presents as scaling papules that abruptly appear on the trunk and extremities, sparing the palms and soles. Lesions increase in diameter with time. Streptococcal pharyngitis or a viral upper respiratory tract infection may occur 1 to 2 weeks before cutaneous lesions of guttate psoriasis appear.8

    REFERENCES:

    1. Villalon-Gomez JM. Pityriasis rosea: diagnosis and treatment. Am Fam Physician. 2018;97(1):38-44. Accessed June 3, 2020. https://www.aafp.org/afp/2018/0101/p38.html
    2. Zawar V. Unilateral pityriasis rosea in a child. J Dermatol Case Rep. 2010;4(4):54-56. doi:10.3315/jdcr.2010.1057
    3. Urbina F, Das A, Sudy E. Clinical variants of pityriasis rosea. World J Clin Cases. 2017;5(6):203-211. doi:10.12998/wjcc.v5.i6.203
    4. Chuh A, Zawar V, Sciallis G, Kempf W. A position statement on the management of patients with pityriasis rosea. J Eur Acad Dermatol Venereol. 2016;30(10):1670‐1681. doi:10.1111/jdv.13826
    5. Brown DL, Frank JE. Diagnosis and management of syphilis. Am Fam Physician. 2003;68(2):283‐290. Accessed June 3, 2020. https://www.aafp.org/afp/2003/0715/p283.html
    6. Ely JW, Rosenfeld S, Seabury Stone M. Diagnosis and management of tinea infections. Am Fam Physician. 2014;90(10):702‐710. Accessed June 3, 2020. https://www.aafp.org/afp/2014/1115/p702.html
    7. Habif TP. Eczema and hand dermatitis. In: Habif TP. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 5th ed. Mosby Elsevier; 2010:chap 3.
    8. Habif TP. Psoriasis and other papulosquamous diseases. In: Habif TP. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 5th ed. Mosby Elsevier; 2010:chap 8.

    Answer: Atypical Pityriasis Rosea

    Pityriasis rosea (PR) is a self-limiting skin condition that presents as discrete scaly papules and plaques located along the trunk and limbs.1 The diagnosis of PR in its classical form is made clinically, but variants do exist.

    Atypical forms of PR are relatively common, presenting in approximately 20% of patients. The variants are diverse in their symptoms, morphology, and location of lesions.2 Pityriasis circinata et marginata presents in adults with few large lesions in a limb-girdle distribution. Inversus PR has skin findings in the flexural areas, face, and neck. The PR of the extremities variant has squamous plaques that are confined to the extremities. Papular PR presents as small papular lesions on the proximal extremities.3 

    Skin biopsy will yield focal parakeratosis with or without acanthosis, spongiosis, or a perivascular infiltrate of lymphocytes and histiocytes, and occasionally extravasation of red cells.4

    Treatment is aimed at controlling symptoms and consists of corticosteroids or antihistamines. In some cases, acyclovir can be used to treat symptoms and reduce the length of disease. For severe cases, ultraviolet phototherapy can be considered.1

    DIFFERENTIAL DIAGNOSIS

    The rash associated with secondary syphilis may present with macular, maculopapular, or even pustular lesions. The rash of secondary syphilis usually begins on the trunk and proximal extremities and may involve all skin surfaces, including the palms and soles. Secondary syphilis also may be associated with fever, malaise, generalized lymphadenopathy, arthralgias, weight loss, and other constitutional symptoms.5

    Tinea corporis is a fungal infection of the face, trunk, or extremities that presents with red, annular, scaly, pruritic patches and plaques with raised scaly borders that expand peripherally with central clearing.6 The lesions may be single or multiple, with the size usually ranging from 1 to 5 cm; however, larger lesions and confluence of lesions also may be present.6

    Nummular eczema typically presents as a coin-shaped (nummular) red plaques on the skin that may be pruritic. The scale is thin and sparse. Lesions tend to not increase in size, although they may become more numerous. The dorsal hand is most commonly involved.7

    Guttate psoriasis presents as scaling papules that abruptly appear on the trunk and extremities, sparing the palms and soles. Lesions increase in diameter with time. Streptococcal pharyngitis or a viral upper respiratory tract infection may occur 1 to 2 weeks before cutaneous lesions of guttate psoriasis appear.8

    REFERENCES:

    1. Villalon-Gomez JM. Pityriasis rosea: diagnosis and treatment. Am Fam Physician. 2018;97(1):38-44. Accessed June 3, 2020. https://www.aafp.org/afp/2018/0101/p38.html
    2. Zawar V. Unilateral pityriasis rosea in a child. J Dermatol Case Rep. 2010;4(4):54-56. doi:10.3315/jdcr.2010.1057
    3. Urbina F, Das A, Sudy E. Clinical variants of pityriasis rosea. World J Clin Cases. 2017;5(6):203-211. doi:10.12998/wjcc.v5.i6.203
    4. Chuh A, Zawar V, Sciallis G, Kempf W. A position statement on the management of patients with pityriasis rosea. J Eur Acad Dermatol Venereol. 2016;30(10):1670‐1681. doi:10.1111/jdv.13826
    5. Brown DL, Frank JE. Diagnosis and management of syphilis. Am Fam Physician. 2003;68(2):283‐290. Accessed June 3, 2020. https://www.aafp.org/afp/2003/0715/p283.html
    6. Ely JW, Rosenfeld S, Seabury Stone M. Diagnosis and management of tinea infections. Am Fam Physician. 2014;90(10):702‐710. Accessed June 3, 2020. https://www.aafp.org/afp/2014/1115/p702.html
    7. Habif TP. Eczema and hand dermatitis. In: Habif TP. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 5th ed. Mosby Elsevier; 2010:chap 3.
    8. Habif TP. Psoriasis and other papulosquamous diseases. In: Habif TP. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 5th ed. Mosby Elsevier; 2010:chap 8.