:Granular parakeratosis

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Granular parakeratosis, also known as axillary granular parakeratosis, intertriginous granular parakeratosis, and zombie patch is a cutaneous condition characterized by brownish-red keratotic papules that can coalesce into plaques.{{cite book |author=Rapini, Ronald P. |author2=Bolognia, Jean L. |author3=Jorizzo, Joseph L. |title=Dermatology: 2-Volume Set |publisher=Mosby |location=St. Louis |year=2007 |isbn=978-1-4160-2999-1 }}

Signs and symptoms

Granular parakeratosis frequently affects the folds and is characterized by erythema with variable degrees of hyperpigmentation. In certain people, it may also be significantly pruritic.{{cite journal | last1=Lin | first1=Qingxia | last2=Zhang | first2=Dong | last3=Ma | first3=Weiyuan | title=Granular Parakeratosis: A Case Report | journal=Clinical, Cosmetic and Investigational Dermatology | publisher=Informa UK Limited | volume=15 | year=2022 | issn=1178-7015 | doi=10.2147/ccid.s371558 | doi-access=free | pages=1367–1370| pmid=35874456 | pmc=9297043 }}

Causes

The exact cause of granular parakeratosis is unclear. The majority of reports elaborate links with skin maceration (due to occlusion,{{cite journal | last1=Northcutt | first1=Alan D. | last2=Nelson | first2=Donna M. | last3=Tschen | first3=Jaime A. | title=Axillary granular parakeratosis | journal=Journal of the American Academy of Dermatology | publisher=Elsevier BV | volume=24 | issue=4 | year=1991 | issn=0190-9622 | doi=10.1016/0190-9622(91)70078-g | pages=541–544| pmid=2033126 }} warm surroundings,{{cite journal | last=G | first=Rodríguez | title=[Axillary granular parakeratosis] | journal=Biomedica: Revista del Instituto Nacional de Salud | date=2002 | publisher=Biomedica | volume=22 | issue=4 | pages=519–523 | doi=10.7705/biomedica.v22i4.1178 | issn=0120-4157 | pmid=12596449 | doi-access=free | url=https://www.redalyc.org/pdf/843/84322411.pdf }} perspiration, obesity, and recurrent washing{{cite journal | last1=Neri | first1=Iria | last2=Patrizi | first2=Annalisa | last3=Guerrini | first3=Valentina | last4=Fanti | first4=Pier Alessandro | title=Granular Parakeratosis in a Child | journal=Dermatology | publisher=S. Karger AG | volume=206 | issue=2 | year=2003 | issn=1018-8665 | doi=10.1159/000068454 | pages=177–178| pmid=12592091 | s2cid=44618750 }}) or skin irritation from external chemicals (eg, antiperspirants, deodorants, and zinc oxide). It appears to be a reactive process in the skin.{{cite journal | last1=Ding | first1=Catherine Y. | last2=Liu | first2=Hannah | last3=Khachemoune | first3=Amor | title=Granular Parakeratosis: A Comprehensive Review and a Critical Reappraisal | journal=American Journal of Clinical Dermatology | publisher=Springer Science and Business Media LLC | volume=16 | issue=6 | date=2015-08-05 | issn=1175-0561 | doi=10.1007/s40257-015-0148-2 | pages=495–500| pmid=26242230 | s2cid=207482401 }} In case reports, exposure to benzalkonium chloride—a preservative and antiseptic used in a wide range of goods, such as medical treatments, laundry rinses, and wipes—has been suggested as a trigger.{{cite journal | last1=Robinson | first1=Aaron J | last2=Foster | first2=Rachael S | last3=Halbert | first3=Anne R | last4=King | first4=Emma | last5=Orchard | first5=David | title=Granular parakeratosis induced by benzalkonium chloride exposure from laundry rinse aids | journal=Australasian Journal of Dermatology | publisher=Wiley | volume=58 | issue=3 | date=2016-09-19 | pages=e138–e140 | issn=0004-8380 | doi=10.1111/ajd.12551 | pmid=27641714 | hdl=11343/291746 | s2cid=263094709 | hdl-access=free }} There have also been reports of granular parakeratosis developing after using a depilatory lotion.{{cite journal | last1=A | first1=Samrao | last2=M | first2=Reis | last3=G | first3=Niedt | last4=D | first4=Rudikoff | title=Granular parakeratosis: response to calcipotriene and brief review of current therapeutic options | journal=Skinmed | date=2010 | volume=8 | issue=6 | pages=357–359 | issn=1540-9740 | pmid=21413654 |url=https://pubmed.ncbi.nlm.nih.gov/21413654/ | access-date=2024-03-09 }}

Diagnosis

Granular parakeratosis skin biopsies reveal compact parakeratosis and hyperkeratosis in the stratum corneum.{{cite web | title=UpToDate | website=UpToDate |url=https://www.uptodate.com/contents/granular-parakeratosis | access-date=2024-03-09}} The characteristic feature of the illness is the presence of basophilic keratohyalin granules in cells in the higher layers of the skin.{{cite journal | last1=Ip | first1=Ken Hiu-Kan | last2=Li | first2=Angela | title=Clinical features, histology, and treatment outcomes of granular parakeratosis: a systematic review | journal=International Journal of Dermatology | publisher=Wiley | volume=61 | issue=8 | date=2022-01-30 | issn=0011-9059 | doi=10.1111/ijd.16107 | pages=973–978| pmid=35094385 | pmc=9546368 }} Most frequently, papillomatosis or an acanthotic pattern of thickening of the epidermis occurs with or without psoriasis. There may also be a low-grade lymphohistiocytic infiltration.

Treatment

After stopping the stimulant, some people heal on their own. Oral isotretinoin,{{cite journal | last1=Webster | first1=Cynthia G. | last2=Resnik | first2=Kenneth S. | last3=Webster | first3=Guy F. | title=Axillary granular parakeratosis: Response to isotretinoin | journal=Journal of the American Academy of Dermatology | publisher=Elsevier BV | volume=37 | issue=5 | year=1997 | issn=0190-9622 | doi=10.1016/s0190-9622(97)70119-1 | pages=789–790| pmid=9366832 }} antimicrobial medications, topical glucocorticoids,{{cite journal | last1=Chamberlain | first1=A. J. | last2=Tam | first2=M. M. | title=Intertriginous granular parakeratosis responsive to potent topical corticosteroids | journal=Clinical and Experimental Dermatology | publisher=Oxford University Press (OUP) | volume=28 | issue=1 | year=2003 | issn=0307-6938 | doi=10.1046/j.1365-2230.2003.01159.x | pages=50–52| pmid=12558631 | s2cid=33504233 }} tretinoin,{{cite journal | last1=Brown | first1=Sonya K. | last2=Heilman | first2=Edward R. | title=Granular parakeratosis: Resolution with topical tretinoin | journal=Journal of the American Academy of Dermatology | publisher=Elsevier BV | volume=47 | issue=5 | year=2002 | issn=0190-9622 | doi=10.1067/mjd.2002.109252 | pages=S279–S280| pmid=12399751 }} and vitamin D3 derivatives have also been reported to be beneficial.{{cite journal | last1=Contreras | first1=Michael E. | last2=Gottfried | first2=Lisa C. | last3=Bang | first3=Ran H. | last4=Palmer | first4=Charles H. | title=Axillary intertriginous granular parakeratosis responsive to topical calcipotriene and ammonium lactate | journal=International Journal of Dermatology | publisher=Wiley | volume=42 | issue=5 | year=2003 | issn=0011-9059 | doi=10.1046/j.1365-4362.2003.01722.x | pages=382–383| pmid=12755978 | s2cid=9695747 }} Additionally, successful treatments with freezing, injections of botulinum toxin, and the combination of Nd: YAG and CO2 fractional laser therapy have been reported.

References

External links

[https://dermnetnz.org/topics/granular-parakeratosis DermNet]
[https://www.ncbi.nlm.nih.gov/books/NBK556094/ StatPearls]

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Category:Papulosquamous hyperkeratotic cutaneous conditions