Retiform parakeratosis L41.81

Politzer, Santi and Unna, 1890; in 1902 Brocq assigned the disease to the parapsoriasis group.

The term "parakeratosis variegata" has today only a historical meaning. This poikilodermic clinical picture is assigned to the group of "large-cell parapsoriasis en plaques" (see below Parapsoriasis en plaques large-cell poikilodermic form). The particular clinical aspect with the "striar or reticular arranged, lichenoid and atrophic, little scaling papules and plaques does not justify an autonomy of the disease pattern. Newer literature on this clinical picture is only sporadically available.

Anular, striated or reticularly arranged, lichenoid papules and plaques. These are aligned in places in the cleft lines of the skin. If net-like formations are formed, they appear to follow the deep vascular plexus of the skin (misinterpretation as livedo). Plaques confluent (random confluence patterns) to larger inhomogeneously patterned areas in which two-dimensional elevations alternate with atrophy. Peripheral brownish spots (pigmentation) and telangiectasia are also found. If the capillitium is affected, focal or diffuse (scarring) alopecia can occur.

Partially atrophic but slightly acanthotic epithelium mostly with compact orthokeratosis or orthohyperkeratosis. Only rarely there is patchy parakeratosis. Bulky, diffuse, sparsely pleomorphic lymphoid cellular infiltrate in a band-like subepithelial arrangement. The upper dermis is distended with numerous dilated vessels. Focal epidermotropy with minor spongiosis of the epidermis. Sporadic cytoid corpuscles are found. Pautrier's microabscesses are possible. Pigment incontinence.

Electron microscopy: Lutzner cells in the epidermis.

Pityriasis lichenoides chronica; lichen planus atrophicans; poikilodermic dermatomyositis; lupus erythematosus.

Histologic: lichen planus atrophicans; eczema pattern; already realized cutaneous T-cell lymphoma; aphlegmatic form of tinea corporis.

In mild cases, bland-nursing therapy. In severe forms, try UVA irradiation, PUVA therapy or helioclimatic therapy. Six-monthly clinical and, if necessary, histological check-ups are important. If histological confirmation of a cutaneous T-cell lymphoma is available, correspondingly adapted therapeutic measures should be taken.

Chronic course over years to decades. Transition to cutaneous T-cell lymphoma in approximately 10% of cases (5-45% depending on literature; Torai R et al. 2022).

Three years ago, the 65-year-old patient had red, asymptomatic spots on both forearms for the first time, which slowly spread over the months to the trunk, especially the buttocks and breasts, as well as to parts of the extremities near the trunk. The patient complained of moderate itching, especially in the evening. HV became more pronounced after warm showers or baths.

Findings: Exertional dyspnea (condition after myocardial infarction and multiple stents) anemic (hypochromic microcytic anemia, HB 7.4 g/dL). Normothyroid goiter nodosa and well-controlled type II diabetes. Normal leukocyte values, no lymphocytosis, leukocyte differentiation o.B. Songraphy: o.B.; no subcutaneous lymph node enlargements.

Skin status: Anular, sometimes striated or reticular, lichenoid red papules and plaques up to 8 cm in diameter. These are aligned in places in the cleavage lines of the skin. When reticular formations form, they appear to follow the deep vascular plexus of the skin (misinterpretation as livedo). Plaques confluent (random confluence patterns) to form larger inhomogeneously patterned areas in which planar elevations alternate with atrophies. On the buttocks 6 cm, large, flat ulcer embedded in lesional skin.

Histology: S.o. findings. Immunohistology: CD3+. CD4+, MiB 15% reactive. No evidence of clonal rearrangement of T cell receptor genes.

Therapy: Iron substitution, continuation of antidiabetic treatment. Local: Bland caring therapy. PUVA-bath-therapy, 4 times/week 0,2-0,3 J/cm2, with every 3rd therapy unit increase of the dose by 0,2 J/cm2); under it after 14 days clear improvement of the clinical findings, itching satisfyingly regressed. Outpatient continuation of PUVA therapy (3 times/week) until further notice.

Further procedure: Clinical and, if necessary, histological control examinations are necessary. Repetition of the T-cell receptor gene rearrangement. Otherwise symptomatic (follow-up) non-aggressive treatment.

1. Holubar K (2003) Psoriasis and parapsoriasis: since 200 and 100 years, respectively. J Eur Acad Dermatol Venereol 17: 126-127
2. Karenko L et al (2003) Chromosomal abnormalities in relation to clinical disease in patients with cutaneous T-cell lymphoma: a 5-year follow-up study. Br J Dermatol 148: 55-64
3. Popp C et al (1992) Considerations on the pathogenesis of parakeratosis variegata based on morphologic and molecular genetic findings. Dermatologist 43: 634-639
4. Torai R et al (2022) Adult T-cell leukemia/lymphoma showing parakeratosis variegata. Int J Dermatol 61:e59-e61.
5. Wolf IH et al (2009) Parapsoriasis lichenoides/parapsoriasis variegata--a new concept. J Dtsch Dermatol Ges 7:993-995.