Intertriginous psoriasis L40.84

Mostly chronic variant of psoriasis (see also psoriasis vulgaris) that predominantly affects the large skin fold areas(psoriasis inversa).

Intertriginous psoriasis may "accompany" classic psoriasis vulgaris. In most cases, however, the intertriginous zones are free in this form.

However, intertriginous psoriasis can also affect the intertriginous zones in isolation (and this actually defines the term "psoriasis intertriginosa"). Since the clinical picture is quite different from the classic distributed psoriasis vulgaris, (isolated) intertriginous psoriasis presents a particular diagnostic challenge.

There are sharply defined, frequently itchy, usually macerated, red, fully filled 5.0 - 10.0 cm large or larger, spots or very flat sometimes weeping plaques; no prominent edge accentuation (DD Tinea intertriginosa); no satellite foci (as in intertriginous candidiasis), no central healing pattern.

The typical psoriatic scaling is always absent.

Often itching is the main symptom. This applies particularly to genital and perianal psoriasis vulgaris. In these cases, the itching can be excruciating, especially at higher outside temperatures.

In cases of severe itching, superimposed scratching effects, also extensive maceration and sweetishly unpleasant local foetus due to secondary microbial colonisation are impressive.

For axillary and inguinal infestation

Frequently:

• Tinea corporis: At the time of first diagnosis, this shows one or more inflammatory reddened, slightly scaly plaques with edges and a centrifugal expansion tendency and central healing. There is almost always a marked itching. Mycological proof!
• Candidosis, intertriginous: Sharply defined, peripherally scaly erythema and plaques. Frequently pustule fringe or splashes of papulovesicular to pustular satellites in the surroundings. Mycological evidence!
• Intertrigo: Mostly obese patients; clinical signs: High red, usually sharply defined (satellite foci indicate intertriginous candidiasis or contact allergic eczema), extensive, itchy or painful erosions, spots or erosive plaques and often rhagades. An unpleasant sweetish fetus indicates a bacterial superinfection.

Rarely:

• Pemphigus chronicus benignus familiaris: Long-standing finding; more frequent in the intertriginous regions; familial accumulation. Itchy, reddened, roundish, oval or circulatory plaques covered by greasy scale crusts, usually sharply defined with typical transverse fissures (typical sign). Often secondary infections (e.g. with candida). Nikolski phenomenon is positive.

With perianal infestation:

Often:

• Anal eczema (see also differential diagnosis of anal eczema)
• Candidosis
• M. Crohn
• Atopic Anal Eczema
• Lichen simplex chronicus Vidal
• lichen sclerosus et atrophicus
• lichen planus

Rare:

• Pemphigus chronicus benignus familiaris
• Dyskeratosis follicularis (M. Darier).
• Bowen's disease
• Paget's disease, extramammary

It is not uncommon for bacterial or mycotic (Candida species) superposition of the intertriginous plaques to occur.

• Mild form: In the case of a few, smaller, uncomplaining intertriginous plaques, only nourishing external agents are used. The use of simple zinc ointment R296 has proven effective. Cleaning of the affected intertriginous areas with peanut or castor oil. If mycotic overgrowth is present, 1% clotrimazole in zinc ointment R058 is recommended.
• Alternatively, an ointment containing calcipotriol(e.g., Daivonex, Psorcutan) can be applied (note irritation potential of ointments!). Calcipotriol and tazarotene are usually too irritating intertriginally. Tacalcitol (Curatoderm) can be used 1 time/day on a trial basis.
• Alternatively, consider using the calcineurin inhibitors tacrolimus (off-label use) and pimecrolimus (off-label use). The clinical results are remarkably good. Caution. High therapy costs! However, because of the unknown long-term effects of calcineurin inhibitors and the carcinogenicity of pimecrolimus demonstrated in animal studies, the indication for therapy with calcineurin inhibitors must be extremely strict!
• Large-surface, less irritated form: Non-aggressive local therapy. Initial application of a zinc ointment. Astringent sitz baths with synthetic tannic acid (e.g. Tannolact solution, Tannosynt liquid). Cleaning of the areas with pure olive, castor or peanut oil. Application of a bandage (preferably gauze compresses, TG tubular bandage or cotton underpants). If no satisfactory treatment success can be achieved, the application of a soft dithranol-zinc paste is recommended: application overnight; start with a 0.05% soft dithranol-zinc paste R078 if necessary increase the concentration after 1 week (e.g. to 0.1% dithranol).
• Large, irritated, possibly weeping form: exclusion of superimposed mycoses by smear and culture! In case of suspicion, short-term combination preparation of glucorticoid/azole antimycotic (e.g. Vobaderm cream). After the acute phase has subsided, discontinuation of glucocorticoids; alternating treatment with a pure base, and finally a nurturing therapy.

Notice. Higher-potency glucocorticoids should be avoided in long-term use in the genito-anal area!

s.a.under Psoriasis Naturopathy

Occlusive effect due to the special topography with great danger of steroid atrophy! After the acute situation has subsided, the application of a soft dithranol-zinc paste is recommended (application especially overnight). The danger of soiling the laundry must be pointed out. Start with a 0.05% soft dithranol-zinc paste R078. If necessary, increase the concentration after 1 week, e.g. to 0.1% Dithranol R078, R070. Regular astringent sitz baths (e.g. with Tannolact) or clover baths (e.g. Töpfer clover bath) are well suited to supplement therapy.

Notice. Patience of therapist and patient is important in dealing with this disease! Basically, it can be said about the therapy with Dithranol that it should only be carried out with patients who show a high compliance!

If these measures are not sufficient, antipsoriatic systemic therapy with fumarates can be used for highly irritated, extensive and therapy-resistant intertriginous psoriasis (for therapy modalities, see Psoriasis vulgaris below).

Other systemic antipsoriatic drugs are also indicated for this specific indication.

In "genital psoriasis", the DISCREET study is the first randomized study with the PDE4 inhibitor apremilast. After 32 weeks, almost 90% of participants were no longer impaired in their sexual health (Merola JF et al. 2024).

1. Avila Alvarez A et al. (2009) Flexural psoriasis induced by infliximab and adalimumab in a patient with Crohn's disease. An Pediatr (Barc) 70:278-281

2. Freeman AK et al. (2003) Tacrolimus ointment for the treatment of psoriasis on the face and intertriginous areas. J Am Acad Dermatol 48: 564-568

3. Merola JF et al. (2024) Efficacy and safety of apremilast in patients with moderate-to-severe genital psoriasis: Results from DISCREET, a phase 3 randomized, double-blind, placebo-controlled trial. J Am Acad Dermatol 90:485-493.

4. Nuño-González A et al. (2012) Flexural or inverse psoriasis in a patient with hidradenitis suppurativa receiving treatment with infliximab. Actas Dermosifiliogr 103:936-937