Pityriasis lichenoides (et varioliformis) acuta L41.0

Mucha, 1916; Habermann, 1925

Often triggered by infectious allergies, inflammatory, self-limited, multiform disease with acute course, with preferential occurrence in the autumn and winter months. About 50% of the patients suffer from pruritus.

Many authors consider pityriasis lichenoides et varioliformis acuta as an acute course form of pityriasis lichenoides, so it can be assumed that they are different acute stages of one and the same entity.

Transitional forms between pityriasis lichenoides et varioliformis acuta (PLEVA) and pityriasis lichenoides chronica (PLC) are possible. They are about 5% in larger collectives.

An extremely rare variant of PLEVA (50 cases in the literature to date) is considered to be the highly febrile ulceronecrotic course (pityriasis lichenoides with ulcers and hyperthermia = PLUH), which is associated with severe morbidity. Another name for this variant is FUMHD.

Incidence is 1:6000/1:12,000

Unknown (immune complex vasculitis?).

Both PLC and PLEVA are lymphoproliferative T-cell disorders.

Suspected causes are infectious-allergic bacterial (hemolytic streptococci), drug-allergic or viral(zoster virus, HHV-7, Epstein-Barr virus; adenoviruses - Costa-Silva M et al. 2017; Horie C et al. 2018).

Occurred in isolated cases after vaccinations (Merlotto MR et al. 2020; Gunatheesan S et al. 2012, Castro BA et al. 2015).

Proximity to cutaneous T-cell lymphomas is discussed (evidence of a monoclonal rearrangement of the T-cell receptor in > 50% of cases!).

The concept of immune complex vasculitis is based on the detection of immunoglobulins and complement in the junctional zone of the skin as well as in walls of dermal vessels.

More frequent in the first two decades of life (6-18 years). Less frequent in infants.

Frequency peaks at 5 and 10 years;

Less frequently adults (middle age around 40 years) are affected.

Male sex preferred (m:w=3:1).

Trunk, flexor sides of extremities; oral mucosa and capillitium remain free (differentiation from varicella).

As in the "Heubner's star chart" (see varicella below), there is a very polymorphic, only moderately itchy, possibly burning, but often (in 50% of patients) completely asymptomatic exanthema.

Acute onset with 0.2-0.4 cm erythema, red or red-brown initially surface-smooth lichenoid papules. These rapidly disintegrate, with lesional formation of erosions, ulcers, and hemorrhagic crusts. Hemorrhagic vesicles are less common. The recurrent and relapsing course of the disease results in a coexistence of different efflorescences, with a correspondingly variegated (as in varicella) overall pattern.

Healing with formation of varioliform scars.

Passenger hyperpigmentation or leukoderma. Pruritus is present in most patients; fever and arthralgias are less common. About 30% of patients have no symptoms.

In rare cases, the disease can be highly febrile with severe general symptoms as well as sudden disseminated crusty ulcerations. Especially in adulthood, this complicating form of the disease (although extremely rare!) can also be lethal.

An extremely rare variant of PLEVA (50 cases in the literature so far) is the highly febrile ulceronecrotic course (pityriasis lichenoides with ulcers and hyperthermia = PLUH), which is associated with severe clinical symptoms.

Occasionally, skin changes indistinguishable from pityriasis lichenoides acuta et varioliformis are also observed in patients with lymphomatoid papulosis.

Not relevant. Inflammation parameters (CRP, BSG) slightly increased.

Interface dermatitis with irregular acanthosis, two-layer structure of the stratum corneum with plexus-like orthokeratosis over a continuous parakeratosis zone. Differently pronounced inter- and intracellular edema in the epidermis up to intraepidermal vesiculation; focal necrosis of the epidermis.

In the dermis wedge-shaped, perivascular or interstitial infiltrate of CD8+ lymphocytes (occasionally mixed with large lymphocytic irritants) and a few neutrophilic granulocytes. A T-cell clonality is often detectable.

Focal erythrocyte extravasations. Swelling of the endothelium, circumscribed erythrocyte diapedesis.

Immunohistology: Mostly_C3 and/or IgM in the vessel walls of the upper dermal plexus.

• Clinical differential diagnoses:
  • Varicella: Clinical morphology may be very similar. Different infestation pattern with involvement of oral mucosa and capillitium.
  • Drug exanthema: No asynchronous polymorphism but rather monomorphic exanthema.
  • Syphilis: Syphilides are usually accompanied by LK swelling, appearance rather monomorphic, frequent involvement of palms and face. Serology is conclusive! Histology is conclusive (plasma cell-rich dermatitis).
  • Tuberculid, papulonecrotic: chronicity, evidence of active tuberculosis.
• Histologic differential diagnoses:
  • Acute and subacute eczema: spongiosis, planar parakeratosis, no keratinocyte necrosis, in atopic eczema possible eosinophilia.
  • Fixed drug reaction: apoptotic keratinocytes, vacuolated junctional zone, satellite necrosis, perivascular lymphocytic infiltrate.
  • Psoriasis guttata: acanthosis, hyper- and parakeratosis with neutrophil inclusions, no keratinocyte necrosis; diffuse, also perivascular condensed lymphocytic infiltrate with neutrophil granulocytes, no erythrocyte extravasations, vigorous epidermotropism.
  • Pityriasis rosea: edema of papillary body, focal spongiosis, no apoptotic keratinocytes, superficial perivascular lymphocytic infiltrate, few eosinophils.
  • Early syphilis: interface dermatitis with psoriasiform epidermal reaction dense, band-like infiltrate in upper and middle dermis (lymphocytes, histiocytes and plasma cells; also epithelioid cell component. Extension of the infiltrate to the deep vascular plexus.

Good experience exists with erythromycin administration(3x500mg/day for 10 days), possibly in combination with glucocorticoids such as prednisolone (e.g. Decortin H initially 1mg/kgKG/day, rapid reduction).

For more severe pruritus, systemic antihistamine such as clemastine (e.g. Tavegil) 1-2 mg/day or desloratadine (e.g. Aerius) 5-10 mg/day p.o..

In the ulceronecrotic, febrile course, methotrexate (7.5-10.0 mg/m2 KO/week p.o. is recommended, possibly in combination with oral glucocorticoids(methylprednisolone 1-2 mg/kg bw/day).

Good response from TNF antagonists has been reported. IVIG (Marenco F et al. 2010) and extracorporeal photopheresis have also been used in individual cases.

Frequent healing after relapse or recurrent course in an average period of 18 months (4-108 months; Ersoy-Evans S et al. 2007).

Transition to pityriasis lichenoides chronica is possible.

Only in rare cases of the febrile, ulceronecrotic form of progression can life-threatening complications develop.

1. Costa-Silva M et al. (2017) Pityriasis lichenoides et varioliformis acuta associated with human herpesvirus 7. Actas Dermosifiliogr. doi: 10.1016/j.ad.2017.03.023.
2. Castro BA et al (2015) Pityriasis lichenoides et varioliformis acuta after influenza vaccine. An Bras Dermatol 90(3 Suppl 1):181-184.
3. de Unamuno Bustos B et al. (2014) Adult pityriasis lichenoides-like mycosis fungoides: a clinical variant of mycosis fungoides. Int J Dermatol 53:1331-1338.
4. Ersoy-Evans S et al (2007) Pityriasis lichenoides in childhood: a retrospective review of 124 patients. J Am Acad Dermatol 56:205-210.
5. Gardlo K et al (2003) PUVA -therapy of severe pityriasis lichenoides et varioliformis acuta. Dermatologist 54: 984-985
6. Gunatheesan S et al (2012) Pityriasis lichenoides et varioliformis acuta: a rare association with the measles, mumps and rubella vaccine. Australas J Dermatol 53:e76-78.
7. Habermann R (1925) On the acute necrotizing subtype of pityriasis lichenoides (pityriasis lichenoides et varioliformis acuta). Dermatol Z 45: 42-48
8. Horie C et al. (2018) Varicella zoster virus as a possible trigger for the development of pityriasis lichenoides et varioliformis acuta: retrospective analysis of our institutional cases. Clinical and experimental dermatology 43:703-707.
9. Marenco F et al (2010) High-dose immunoglobulins and extracorporeal photochemotherapy in the treatment of febrile ulceronecrotic Mucha-Habermann disease. Dermatol Ther 23:419-422.
10. Martinez-Escala ME et al. (2014) γδ T cell-rich variants of pityriasis lichenoides and lymphomatoid papulosis: benign cutaneous disorders to be distinguished from aggressive cutaneous γδ T cell lymphomas. Br J Dermatol doi: 10.1111/bjd.13364.
11. Merlotto MR et al (2020) Pityriasis lichenoides et varioliformis acuta following anti-tetanus and diphtheria adult vaccine. An Bras Dermatol 95:259-260.
12. Miyamoto T et al (2003) Febrile ulceronecrotic Mucha-Habermann disease: a case report and a review of the literature. J Clin Pathol 56: 795-797.
13. Mucha V (1916) On a peculiar case close to parakeratosis variegata (Unna) or pityriasis lichenoides chronica (Neisser-Juliusberg). Arch Dermatol Syph 123: 586-592
14. Nofal A et al (2016) Febrile ulceronecrotic Mucha-Habermann disease: proposed diagnostic criteria and therapeutic evaluation. Int J Dermatol 55:729-738.
15. Weinberg JM et al (2002) The clonal nature ot pityriasis lichonides. Arch Dermatol 138: 1063-1067.