Types of Psoriasis – FLEXURAL/INTERTRIGINOUS (INVERSE PSORIASIS) and GENITAL PSORIASIS

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Inverse psoriasis

 also known as flexural or intertriginous psoriasis is a rare form of psoriasis that occurs in the flexural skin folds. Plaque psoriasis is most commonly found on the trunk and extensor surfaces of the body, such as the knees, elbows, sacral (lower back) area, and scalp whereas Inverse psoriasis is found in the folds of the axilla (armpits), submammary (breast) folds, and groin (inguinal) and buttock folds. It can occur in any area where two skin surfaces meet. The inguinal fold is the most commonly affected area, followed by the axilla and the external genitalia. The skin at the inverse body sites differs from skin at extensor sites with less epidermal keratinization (thinner skin) and more sweat glands. The most evident difference between classical plaque-type psoriasis and inverse psoriasis is the lack of, or less, scaling. The lesions are usually well demarcated, erythematous (red), and are often shiny, appear moist, weepy and fissured. The irritation may be increased in inverse psoriasis as a result of the rubbing and sweating involved in the skin folds. 1, 2   

Approximately 3–7% of psoriasis patients present with inverse psoriasis and patients with palmar psoriasis have a greater chance of having inverse psoriasis as compared with plaque psoriasis. In one study of 170 psoriasis patients with palmar involvement, 5.3 times more patients had inverse psoriasis than patients with plaque psoriasis. Development of inverse psoriasis has been reported as a paradoxical side effect to treatment with infliximab for Crohn’s disease and hidradenitis suppurativa. Inverse psoriasis has been observed to be more common in the obese population possibly due to the rubbing of the skin folds. 1, 2

Inverse psoriasis affecting the genitalia seems to be underreported and undertreated; and approximately 35% patients with genital psoriasis never speak to their physician about their genital lesions. Nearly 70% of Physicians do not offer treatment for genital lesions. 3

Flexural Psoriasis 3

A study on the quality of life and sexual life in 487 patients with genital psoriasis concluded that3:

  • patients with genital lesions report even significantly worse quality of life than patients without genital lesions;
  • sexual distress and dysfunction are particularly prominent in women;
  • sexual distress is especially high when genital skin is affected;
  • the attention given to possible sexual problems in the psoriasis population by healthcare professionals is perceived as insufficient by patients.     

Flexural Psoriasis 2

Results of several questionnaire-based surveys show that involvement of the genital skin region occurs in 29–40% of patients with psoriasis. The genital area may frequently be involved in cases of inverse psoriasis. Of 48 patients with inverse psoriasis, the external genitalia were involved in 38 (79.2%). 4

Flexural Psoriasis 1

In another report researchers stated that patients with genital psoriasis have significantly worse quality of life (QoL) scores compared with patients without genital lesions. In addition, numerous patients with psoriasis have sexual dysfunction. Between 25–40% of patients reported a decline of sexual activity since the onset of psoriasis, mainly due to diminished sexual desire, embarrassment of physical appearance and inconvenience caused by scaliness of the skin or topical therapy. Particularly in women with genital psoriasis, sexual distress is higher and sexual function is more significantly impaired compared to those without genital lesions. 4

Inverse psoriasis is often misdiagnosed for bacterial or fungal intertrigo. Intertrigo is inflammation of opposed skin folds caused by skin-on-skin friction that presents as erythematous, macerated (moist, broken, soft skin) plaques. Secondary bacterial and fungal infections are common because the moist, denuded skin provides an ideal environment for growth of microorganisms. Candida is the most common fungal organism associated with intertrigo. Intertriginous candidiasis also presents as well demarcated, erythematous patches but with tell tale satellite papules or pustules at the periphery (around the edges). Candida, Staphylococcus aureus and Malassezia furfur have been shown to colonize psoriatic skin lesions so diagnosis for flexural psoriasis is sometimes not easy. Candida species have been isolated from the skin of 15% of psoriasis patients compared to only 4% in the control group. 5, 6 However, some studies have also suggested that Candida is not commonly found in psoriatic lesions of inverse of genital psoriasis.

Application of topical treatment in the intertriginous areas is considered as treatment under occlusion due to enhanced hydration and increased skin absorption. However, the inverse areas are considered more sensitive and prone to side effects from topical steroids (i.e. due to thinner skin at these locations). 2

 

REFERENCES

  1. Syed Z. U. and Khachemoune A.; Inverse Psoriasis Case Presentation and Review; Am J Clin Dermatol 2011; 12 (2): 1-4 1175-0561/11/0002-0001/$49.95/0
  2. Silje Haukali Omland  and Robert Gniadecki; Psoriasis inversa: A separate identity or a variant of psoriasis vulgaris?; Clinics in Dermatology (2015) 33, 456–461
  3. Meeuwi  K.A.P. et al.; Genital Psoriasis: A Systematic Literature Review on this Hidden Skin Disease;  Acta Derm Venereol 2011; 91: 5–11
  4. Meeuwis KAP, et al.; Genital Psoriasis Awareness Program: Physical and Psychological Care for Patients with Genital Psoriasis. Acta Derm Venereol. 2015, 95, 211–216
  5. Wilmer E.N. et al.; Resistant “Candidal Intertrigo” ”: Could Inverse Psoriasis Be the True Culprit?; doi: 10.3122/jabfm.2013.02.120210
  6. Taheri Sarvtin, et al.;. Evaluation of candidal colonization and specific humoral responses against Candida albicans in patients with psoriasis. International Journal of Dermatology. Dec2014,Vol.53Issue12, pe555-e560. 6p.

Types of Psoriasis – GUTTATE PSORIASIS (GP)

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Guttate means “drop” in Latin (also known as Teardrop Psoriasis, Raindrop Psoriasis or Psoriasis Exanthematic), and is the second most common type of psoriasis. Guttate psoriasis (GP), is an important clinical variant which occurs more commonly in adolescents and young adults. It is characterized by the sudden onset of widely dispersed small red scaly plaques – 0.2 – 2.0 cm’s in diameter, mainly over the trunk and proximal limbs. The symptoms of GP are numerous small, bright red or salmon coloured, drop-like spots which cover a large portion of the skin. Spots have an abundant fine scaling. The lesions are usually located on the trunk, arms, legs and scalp and spares the face, palms and soles.1

GP represents approximately 2% of psoriasis patients and 30% of guttate patients have a first degree family member with psoriasis 2. Among patients with acute guttate psoriasis, 56–98% experienced a streptococcal infection (e.g. tonsillitis, viral respiratory infections, laryngitis etc.) within a 2-3 weeks period prior to the eruption and, it is theorized that psoriasis may be induced in susceptible individuals by streptococcal superantigens. In children perianal streptococcal infections (or chronic pruritus of the anus) have also been associated with GP 3.

Because some cases of GP in childhood may be triggered or exacerbated by streptococcal pharyngeal infections, the role of tonsillectomy as a treatment option in severe refractory GP has been studied. However, the results remain controversial and at best non conclusive. In a Cochrane review the conclusion that tonsillectomy may be a successful treatment modality in selected patients with recalcitrant GP is suspect due to the fact that many of the studies were not of a high enough standard for the conclusions to be definitive.5 A study in 2012 which was a blind study found that patients with chronic GP and a history of disease exacerbation in association with sore throat, generally improved after a tonsillectomy.6

Many other infectious agents have also been implicated, although the exact frequency of GP associated with these infections/diseases is unknown.

They include the following:

  • Bacteria – other than Staphylococcus aureus – Enterococcus faecalis, Escherichia coli, Pseudomonas and Proteus species, or the bacterium implicated in duodenal ulceration, Helicobacter pylori.5
  • Fungi – Malassezia, Candida
  • Viruses – Flu, Human papillomavirus (HPV), varicella-zoster virus, human endogenous retroviruses (HERVs) e.g. cytomegalovirus and vaccinations 7.
  • Drugs (including biologic agents) sometimes cause a guttate-type flare.

The most commonly implicated drugs in association with either the initiation or exacerbation of GP include lithium, beta-blockers, antimalarial, and non steroidal anti-inflammatories. 

Immunomodulatory drugs such as infliximab, etanercept, imatinib, and adalimumab have also been reported to initiate GP. The Koebner Phenomenon e.g. tattoos, insect bites scratches etc. can trigger GP.

Approximately 70% of patients with GP will go on to develop chronic plaque psoriasis within a 10 year time frame.

For more information read Our BLOG “PSORIASIS – THE RELATIONSHIP WITH VIRAL, BACTERIAL AND FUNGAL INFECTIONS?”

Guttate with fine scale                        Guttate with no scale

Figure 1. Scattered drop like lesions                                Figure 2. Reddish – scattered drop like lesions

ranging from 0.5 to 2.0 cm, with slight scale.                   ranging from 0.2 to 1.0 cm with no scale.

Coalesing Guttate 4                     Coalesing Guttate 3

Figure 3. Note the fine scale and the                              Figure 4. Note the fine scale and the complete

coalescing (merging) of the lesions.                               merging of the lesions.

Coalesing Guttate                      Coalesing Guttate 2

Figure 5. Reddish lesions – where the                                      Figure 6. Salmon pink lesions – where the             

majority of the lesions have merged.                                       majority of the lesions have merged.

REFERENCES

  • Zangeneh F.Z., Shooshtary F.S.; Psoriasis — Types, Causes and Medication – Chapter 1; http://cdn.intechopen.com/pdfs-wm/44173.pdf
  • Mallbris et al.: Psoriasis Phenotype at Disease Onset: Clinical Characterization of 400 Adult Cases; Journal of Investigative Dermatology; Volume 124, Issue 3, March 2005, Pages 499–504
  • Honig J.; Guttate psoriasis associated with perianal streptococcal disease; Clinical and laboratory observations The Journal of Pediatrics December 1988
  • Telfer NR,Chalmers RJ, Whale K, Colman G. The role of streptococcal infection in the initiation of guttate psoriasis. Archives of Dermatology 1992;128(1):39-42.
  • Antistreptococcal interventions for guttate and chronic plaque psoriasis (Review) 8 Copyright © 2016 The Cochrane Collaboration. http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD001976/epdf
  • Thorleifsdottir R.H. et al.; Improvement of Psoriasis after Tonsillectomy Is Associated with a Decrease in the Frequency of Circulating T Cells That Recognize Streptococcal Determinants and Homologous Skin Determinants; The Journal of Immunology; April 9, 2012, doi:10.4049/jimmunol.1102834
  • Moon Seub Shin et al; New Onset Guttate Psoriasis Following Pandemic H1N1 Influenza Vaccination; Ann Dermatol. 2013 November; 25(4): 489–492.