Lymphocytic infiltrates Flashcards
Pseudolymphoma - overview
- Benign lymphoid proliferation in the dermis
- Can be of B or T cell origin –> specific B cell subtype is lymphocytoma cutis
Pseudolymphoma epidemiology
- Under 40s
- Female > Males
Pseudolymphoma triggers
- Skin trauma
- Needles - tattoos, vaccination, acupuncture
- Infections:
- T cell –> nodular scabies, arthropod bite
- B cell –> Borrelia, Leishmaniasis, Molluscum, Herpes
- Medications - could have started years prior:
- Anti-convulsants
- Anti-hypertensives: ACEI, beta-blockers
- Anti-depressants
- Anti-rheumatics
- Cytotoxic
Clinical - pseudolymphoma B cell
B cell:
Solitary or multiple, itchy or asymptomatic, dermal papules or nodules
Can be subcutaneous
T cell:
Solitary or scattered papules, nodules, plaques
Can present as persistent erythema, or rarely erythroderma
Rarely associated with systemic changes: lymphadenopathy, low grad fever, headache, malaise, arthralgia
Have guarded prognosis as can rarely transform to lymphoma.
Pseudolymphoma histology
- Will show T or B cell lymphoid proliferation
- B presents as nodular, T is nodular or band like
- There is minimal atypical cytology and minimal epidermotropism
- Has normal T cell phenotype, TCR and immunoglobulin gene analysis in polyclonal pattern
Pseudolymphoma investigations
- If suspect drug - eosinophils, LFT
- If suspect infectious cause - Borrelia, swab for viral, etc
- If suspect contact dermatitis –> patch test
Pseudolymphoma management
- Remove suspected cause
- Topical steroids/intra-lesional steroids
- If generalised - plaquenil
Pit lichenoides epidemiology
- PLC most common type
- Children, young adults, lasts on average 18 months
- M>F
- FUMHD most common second or third decade of life
Pit lichenoides preceding factors
- Medications - chemotherapeutic, oral contraceptives, astemizole (anti-histamine), TNF alphas, statins
- Herbs
- Infective
- Viral: CMV, EBV, HSV, HIV, MMR
- Bacterial: mycoplasma, staph, strep
- Parasite: toxoplasmosis
- Diseases associated: MF, parapsoriasis
PLEVA clinical
Initial lesion: oedematous pink papule that undergoes central vesiculation and haemorrhagic necrosis.
Develops in crops, morphologically polymorphic. Subsequent lesions can be vesicular or crusted papular (mica-scale). Can be burning/irritation or asymptomatic.
Trunks, thighs, upper arms and flexors
Scars with varioliform scarring
If pregnant, can risk premature labour if involving the cervical os
PLEVA histology
Top heavy lymphocytic infiltrate.
PLEVA:
Parakeratosis
Lichenoid
Extravasation of erythrocytes
Vasculitis (lymphocytic)
Apoptotic keratinocytes and ‘eight’: CD8 T cells
IF: IgM, C3 and fibrin in walls of vessels
Late lesions have parakeratosis and lymphocytic pseudo Munro abscesses and prominent exocytosis of lymphocytes with mild cytological atypia
PLEVA treatment
1st Line: PO abx - erythromycin 2nd line: Adult - NBUVB, acitretin Kids - acitretin 3rd line: Steroids, MTX, cyclosporin, dapsone. Adults can have UVA TNF alpha blockers
PLC clinical
Small, firm, reddish brown lichenoid papules that are 3-10 mm in diameter. Trunk, thighs, upper arms, flexors, acral sites.
Characteristic mica-like scale that can be detached with gentle scraping.
Over 3-4 weeks, become pigmented macules and PIH.
PLC histology
Less severe than PLEVA and more superficial
PLC treatment
1st Line: Topical steroids/tacrolimus 2nd line: Adults: NBUVB, Abx tetracycline or erythromycin Kids - abx 3rd line: Adults: acitretin, MTX, ciclosporin, dapsone, UVA Kids: MTX, ciclosporin, dapsone
