Verrucous Granular Parakeratosis on the Groin: A Case Report

Abstract

Granular parakeratosis is a rare dermatosis characterized by erythematous scaly patches or papules, and plaques, often involving intertriginous areas. In this work, a 73-year-old Chinese male patient presented with a 6-month history of pruritic verrucous papules on the bilateral groin. A skin biopsy was performed and revealed the following: the horny layer showed highly compact hyperkeratosis and parakeratosis with basophilic granules; the epidermis showed obvious acanthosis with psoriasiform hyperplasia. The final diagnosis was verrucous granular parakeratosis. We also reviewed the progress in nomenclature, etiology, clinical manifestations, differential diagnosis and treatment. Different clinical manifestations may represent different clinical entities. Dermatologists should differentiate it from other diseases to make a correct diagnosis. Treatment options should be based on the variable etiologies and clinical manifestations.

Full text

CASE REPORT
Verrucous Granular Parakeratosis on the Groin:
A Case Report
Huixian Li
1
, Hui Li
2
, Qinghua Tian
2
, Xiangang Fang
2
1
Department of Sterilization Supply, Weifang People’s Hospital, Weifang, Shandong, People’s Republic of China;
2
Department of Dermatology, Weifang
People’s Hospital, Weifang, Shandong, People’s Republic of China
Correspondence: Xiangang Fang, Department of Dermatology, Weifang People’s Hospital, 151 Guangwen Street, Weifang, Shandong, 261041, People’s
Republic of China, Tel +86-536-8192561, Email sdlntszqjlb@163.com
Abstract: Granular parakeratosis is a rare dermatosis characterized by erythematous scaly patches or papules, and plaques, often
involving intertriginous areas. In this work, a 73-year-old Chinese male patient presented with a 6-month history of pruritic verrucous
papules on the bilateral groin. A skin biopsy was performed and revealed the following: the horny layer showed highly compact
hyperkeratosis and parakeratosis with basophilic granules; the epidermis showed obvious acanthosis with psoriasiform hyperplasia.
The nal diagnosis was verrucous granular parakeratosis. We also reviewed the progress in nomenclature, etiology, clinical
manifestations, differential diagnosis and treatment. Different clinical manifestations may represent different clinical entities.
Dermatologists should differentiate it from other diseases to make a correct diagnosis. Treatment options should be based on the
variable etiologies and clinical manifestations.
Keywords: granular parakeratosis, verrucous, papule, groin, glucocorticoid, tretinoin
Introduction
Granular parakeratosis (GP) is a rare-acquired self-limiting skin disease. GP presents clinically as hyperkeratotic
erythematous scales or papules which combine to form plaques, mainly involving intertriginous areas.
1,2
Given the
rarity of GP, we report a case of verrucous GP in the groin of an elderly man to get attention of clinicians. The
dermatologic examination revealed multiple gray-white or dark red verrucous papules on the bilateral groin. Histology
showed highly compact hyperkeratosis, parakeratosis with basophilic granules and psoriasiform epidermis hyperplasia.
We also reviewed the progress in nomenclature, etiology, clinical manifestations, differential diagnosis and treatment.
Two main lesions types of GP were documented, including erythematous scales and papules (plaques). We considered
that different clinical manifestations may represent different clinical entities.
Case Presentation
A 73-year-old Chinese male patient presented with a 6-month history of pruritic papules on the bilateral groin. The most
potent steroid and antifungal ointments did not improve the eruptions before he sought evaluation at our hospital. The
medical history was signicant for a cerebral infarction. There was no family history of similar complaints. The
dermatologic examination revealed multiple gray-white or dark red hyperkeratotic papules on a brown background on
the bilateral groin. On closer examination, the hyperkeratotic papules had a verrucous appearance, some of which had
coalesced. The papules were slightly hard on palpation (Figure 1). There were no abnormalities involving the axillae or
perianal folds.
The possible diagnosis included viral warts, seborrheic keratoses, Bowenoid papulosis, Hailey-Hailey disease, Darier
disease, conuent and reticulated papillomatosis, granular parakeratosis, and Langerhans histiocytosis. A skin biopsy was
performed and revealed the following: the stratum corneum showed highly compact hyperkeratosis and parakeratosis
with basophilic granules; the epidermis showed obvious acanthosis with psoriasiform hyperplasia; and lymphocytes
Clinical, Cosmetic and Investigational Dermatology 2023:16 853–857 853
© 2023 Li et al. This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php
and incorporate the Creative Commons Attribution – Non Commercial (unported, v3.0) License (http://creativecommons.org/licenses/by-nc/3.0/). By accessing the work
you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For
permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms (https://www.dovepress.com/terms.php).
Clinical, Cosmetic and Investigational Dermatology Dovepress
open access to scientific and medical research
Open Access Full Text Article
Received: 22 February 2023
Accepted: 25 March 2023
Published: 1 April 2023

inltrated around small vessels in the upper dermis (Figure 2). A fungal microscopic examination and culture were
negative. Based on clinical manifestations and histopathologic features, the nal diagnosis was verrucous GP. The skin
lesions improved after 1 month of a topical glucocorticoid and tretinoin cream. There was no recurrences after 6 months
of follow-up.
Figure 1 (a–c) Multiple gray-white or dark red hyperkeratotic papules on a brown background on the bilateral groin. On closer examination, the hyperkeratotic papules had
a verrucous appearance, some of which had coalesced.
Figure 2 (a and b) The horny layer showed highly compact hyperkeratosis and parakeratosis with basophilic granules (white circle). The epidermis showed obvious
acanthosis with psoriasiform hyperplasia (black circle). Lymphocytes had inltrated around small vessels in the upper dermis. (HE, a x40; b x200).
https://doi.org/10.2147/CCID.S401799
DovePress
Clinical, Cosmetic and Investigational Dermatology 2023:16
854
Li et al Dovepress
Powered by TCPDF (www.tcpdf.org)

Discussion
GP is a rare skin disease characterized by erythematous scaly patches or papules, and plaques, predominantly involving
intertriginous areas. GP was rst described by Northcutt et al
3
in 1991 as an axillary eruption with an exclusive
histopathology and was named “axillary GP”. With the development of recognition of anatomical distribution, the
naming has also evolved.
4
In 1998, Mehregan et al
5
reported a case involving the groin as intertriginous GP, omitting the
word “axillary”. In 1999, Metze et al
6
renamed it GP, acknowledging involvement in non-intertriginous areas and
omitting the word “intertriginous”.
The etiology of GP is unclear, but many theories exist on the possible causes of GP. GP has been thought to respond
to contact antiperspirants and is now considered a disorder of keratinization with an increasing number of potential
pathogenic factors. The rst theory proposed by Northcutt et al was that GP is a contact reaction to local products,
resulting in the disruption of prolaggrin-to-laggrin during epidermal keratinization.
7
Normally, laggrin maintains the
keratohyaline granules in the stratum corneum during keratinization. On the basis of immunohistochemical and ultra-
structural studies,
8
the retention of keratohyaline granules in GP may be attributed to defects in processing prolaggrin-to
-laggrin. Another view holds that GP is caused by an acquired keratosis disorder with unknown etiology and unrelated
to contact. There are cases reported without the use of topical products.
2
This theory is supported by the response of GP
to isotretinoin therapy without identifying triggers.
9,10
Recently, infection has been suggested as a possible cause, as the
skin microbiome of some cases had changed and responded to oral antibiotics.
11,12
For the above-mentioned, GP may be
a response pattern rather than a unique disease entity.
Two main lesions types of GP were reported, including erythematous scales and papules (plaques).
4
The rst feature
of GP is erythematous scales manifested as symmetrical erythema with pathognomonic multi-layer brown epidermal
scales. Kumarasinghe et al rst proposed the term hyperkeratotic exural erythema as a better description for this type.
11
The second feature of GP is papules which can coalesce into plaques with erythematous/brown coloring and hyperker-
atotic texture. However, only 4 cases of verrucous GP, as a special subtype of papular GP, were reported by 2022.
4
Most
patients have itching, burning, tenderness and other symptoms, and a few patients are asymptomatic. The most common
involved sites are intertriginous areas, such as the axilla and groin, most of which are bilateral. A small number of
patients develop eruptions in non-intertriginous areas, such as the face, trunk and thighs.
4
Clinically, the differential diagnosis of GP as erythematous scales includes other diseases, especially those involving
the folds such as seborrheic dermatitis, candidiasis, inverse psoriasis, erythrasma, irritant or allergic contact dermatitis
and Langerhans histiocytosis. The differential diagnosis of GP as papules includes Darier disease, pemphigus vegetans,
conuent and reticulated papillomatosis, viral warts, seborrheic keratoses and even Bowenoid papulosis.
With high clinical suspicion, a skin biopsy is required for histopathological diagnosis. The classic histology of GP is
characterized by thickening of the stratum corneum with retention of keratohyalin granules. Other manifestations may
include parakeratosis, hyperkeratosis, psoriatic or papillomatous epidermal hyperplasia, and supercial dermal lympho-
cyte inltration.
2,4
Different clinical manifestations, including erythematous scales and papules may have different
pathological manifestations. However, it should be emphasized that GP can be just a nonspecic pathological change.
Similar shows to GP are also described in other diseases such as dermatophytosis, molluscum contagiosum, actinic
keratosis.
13
Therefore, dermatologists need to combine clinical manifestations and pathological features to make
appropriate diagnosis.
Because GP is rare, it is difcult to evaluate its therapeutic effect, and several cases of self-healing have been
documented. According to previous reports, initial and important management includes identifying and removing
external products and avoiding occlusion where possible. Second, many kinds of treatments have been used with
different effects, including topical glucocorticoids, calcineurin inhibitors, antibiotics, antifungals, vitamin D3 derivatives,
ammonium lactate, tretinoin, oral isotretinoin, antibacterial agents and botulinum toxin injection. In other cases, physical
therapies such as cryotherapy and Nd:YAG combined with CO
2
fractional laser are also effective.
1,4,13
Since the
prognosis of GP is good and the efcacy varies greatly, treatment should be individualized according to clinical
conditions. Different clinical manifestations including erythematous scales and papules may need different management.
Clinical, Cosmetic and Investigational Dermatology 2023:16 https://doi.org/10.2147/CCID.S401799
DovePress
855
Dovepress Li et al
Powered by TCPDF (www.tcpdf.org)

GP as erythematous scales termed as hyperkeratotic exural erythema may respond to some topical drugs and oral
antibacterial drugs.
11,14
GP as papules may need stronger treatments such as tretinoin, and even some physical therapies.
Our patient was presented with multiple gray-white hyperkeratotic papules with an obvious verrucous appearance on
the bilateral groin. The histologic features include a highly compact hyperkeratosis, parakeratosis with basophilic
granules, and acanthosis with psoriasiform hyperplasia, so the diagnosis of verrucous GP on the groin was made.
Based on the benign characteristics of GP, itching symptoms, lesion types and previous literature, we gave the patient
combined use of a topical glucocorticoid and tretinoin cream, which has improved the lesions.
Conclusions
In conclusion, GP is a rare acquired cutaneous disease characterized by erythematous scales or hyperkeratotic papules typically
involving intertriginous areas. The cause of GP is unknown and may be related to exposure to irritants. In our opinion, GP may be
a reaction pattern rather than a distinct disease and different clinical manifestations may represent different clinical entities, which
needs further research. GP should be differentiated from other skin diseases involving the intertriginous areas due to the rarity,
and a histopathologic examination is essential to conrm the diagnosis. Now no standardized treatment is recommended, and
treatment options should be based on the variable etiologies and clinical manifestations.
Institutional Approval
No institutional approval was required to publish the case details.
Data Sharing Statement
The data that support the ndings of this study are openly available.
Consent Statement
Signed consent was obtained from the patient for the publication of the case details.
Disclosure
All authors have no conicts of interest to declare for this work.
References
1. Ding CY, Liu H, Khachemoune A. Granular parakeratosis: a comprehensive review and a critical reappraisal. Am J Clin Dermatol.
2015;16:495–500. doi:10.1007/s40257-015-0148-2
2. Scheinfeld NS, Mones J. Granular parakeratosis: pathologic and clinical correlation of 18 cases of granular parakeratosis. J Am Acad Dermatol.
2005;52:863–867. doi:10.1016/j.jaad.2004.12.031
3. Northcutt AD, Nelson DM, Tschen JA. Axillary granular parakeratosis. J Am Acad Dermatol. 1991;24:541–544. doi:10.1016/0190-9622(91)70078-
G
4. Ip KH, Li A. Clinical features, histology, and treatment outcomes of granular parakeratosis: a systematic review. Int J Dermatol. 2022;61
(8):973–978. doi:10.1111/ijd.16107
5. Mehregan DA, Thomas JE, Mehregan DR. Intertriginous granular parakeratosis. J Am Acad Dermatol. 1998;39:495–496. doi:10.1016/S0190-
9622(98)70333-0
6. Metze D, Rutten A. Granular parakeratosis – a unique acquire disorder of keratinization. J Cutan Pathol. 1999;26:339–352. doi:10.1111/j.1600-
0560.1999.tb01855.x
7. English JC, Derdeyn AS, Wilson WM, Patterson JW. Axillary granular parakeratosis. J Cutan Med Surg. 2003;7:330–332. doi:10.1007/s10227-
002-0131-4
8. Bolognia JL, Jorizzo JL, Schaffer JV. Dermatology. 3rd ed. Philadelphia, PA: Elsevier, Inc; 2012.
9. Brown SK, Heilman ER. Granular parakeratosis: resolution with topical tretinoin. J Am Acad Dermatol. 2002;47:S279–80. doi:10.1067/
mjd.2002.109252
10. Webster CG, Resnik KS, Guy F. Webster: axillary granular parakeratosis: response to isotretinoin. J Am Acad Dermatol. 1997;37:789–790.
11. Kumarasinghe SP, Chandran V, Raby E, Wood B. Hyperkeratotic exural erythema responding to amoxicillin-clavulanic acid therapy: report of
four cases. Australas J Dermatol. 2019;60:311–314. doi:10.1111/ajd.13069
12. Dear K, Gan D, Stavrakoglou A, Ronaldson C, Nixon RL. Hyperkeratotic exural erythema (more commonly known as granular parakeratosis)
with use of laundry sanitizers containing benzalkonium chloride. Clin Exp Dermatol. 2022;47(12):2196–2200. doi:10.1111/ced.15358
13. Lin Q, Zhang D, Ma W. Granular parakeratosis: a case report. Clin Cosmet Investig Dermatol. 2022;15:1367–1370. doi:10.2147/CCID.S371558
14. Herat A, Gonzalez Matheus G, Kumarasinghe SP. Hyperkeratotic exural erythema/granular parakeratosis responding to doxycycline. Australas
J Dermatol. 2022;63(3):368–371. doi:10.1111/ajd.13868
https://doi.org/10.2147/CCID.S401799
DovePress
Clinical, Cosmetic and Investigational Dermatology 2023:16
856
Li et al Dovepress
Powered by TCPDF (www.tcpdf.org)

Clinical, Cosmetic and Investigational Dermatology Dovepress
Publish your work in this journal
Clinical, Cosmetic and Investigational Dermatology is an international, peer-reviewed, open access, online journal that focuses on the latest
clinical and experimental research in all aspects of skin disease and cosmetic interventions. This journal is indexed on CAS. The manuscript
management system is completely online and includes a very quick and fair peer-review system, which is all easy to use. Visit http://www.
dovepress.com/testimonials.php to read real quotes from published authors.
Submit your manuscript here: https://www.dovepress.com/clinical-cosmetic-and-investigational-dermatology-journal
Clinical, Cosmetic and Investigational Dermatology 2023:16 DovePress
857
Dovepress Li et al
Powered by TCPDF (www.tcpdf.org)