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Acquired hypertrichosis lanuginosa

Malignant down ยท acquired generalised hypertrichosis ยท "werewolf syndrome" (lay term)

Acquired hypertrichosis lanuginosa is a rare but classical paraneoplastic eruption of fine, non-pigmented, lanugo-type hair on the face and trunk in an adult. It carries a strong association with internal malignancy โ€” most often non-small-cell lung carcinoma, colorectal adenocarcinoma, gastric and breast carcinoma. Distinguishing acquired lanugo from drug-induced hypertrichosis (cyclosporin, minoxidil, phenytoin) and endocrine hirsutism is essential because the acquired form mandates an urgent malignancy workup.

CurrentLast reviewed 16 May 2026
Clinical image of Acquired hypertrichosis lanuginosa
Acquired hypertrichosis lanuginosa. Image sourced from DermNet New Zealand. Used under CC BY-NC-ND 4.0. No endorsement implied.

Clinical features

  • Rapid growth of fine, soft, non-pigmented lanugo hair across face, ears, eyelids, neck and trunk; spares palms and soles.
  • Often preceded by glossitis (smooth red painful tongue), weight loss, and other paraneoplastic skin signs (acanthosis nigricans, tripe palms).
  • Onset in middle-aged or older adults. Female predominance.
  • The eruption can precede the diagnosis of malignancy by months to years.

Malignancy associations

  • Lung cancer (non-small-cell, especially adenocarcinoma) โ€” strongest single association.
  • Colorectal adenocarcinoma.
  • Breast carcinoma.
  • Less commonly: gastric, pancreatic, hepatobiliary, ovarian, lymphoma.
  • Mechanism unclear; postulated tumour-derived growth factors reactivate vellus follicles.

Differential diagnosis

  • Drug-induced hypertrichosis: minoxidil, cyclosporin, phenytoin, diazoxide, glucocorticoids, IFN-ฮฑ, EGFR inhibitors. Drug-induced is usually generalised vellus, not strictly lanugo, and improves on drug withdrawal.
  • Endocrine hirsutism: terminal, androgen-pattern, masculinising; PCOS / adrenal / ovarian tumour. Lanugo is non-pigmented and not androgen-pattern.
  • Congenital hypertrichosis lanuginosa: from birth; autosomal dominant; not paraneoplastic.
  • Anorexia nervosa: lanugo growth as part of starvation phenotype.

Workup

  • Full history and examination including breast, abdominal, rectal, lymphadenopathy assessment.
  • Bloods: FBC, U&E, LFT, ESR, CRP, calcium, LDH, tumour markers (CEA, CA 19-9, CA 125, AFP, PSA where indicated).
  • CT chest / abdomen / pelvis.
  • Age- and sex-appropriate screening: mammography, cervical screen, FIT / colonoscopy, gastroscopy if symptomatic.
  • Consider PET-CT when conventional imaging negative.
  • Endocrine review only if features unexplained โ€” measure prolactin / testosterone / DHEAS if there is masculinising change.

Management

  • Treat underlying malignancy โ€” hypertrichosis frequently regresses with successful tumour control.
  • Cosmetic management: shaving / depilatory creams; laser hair removal less effective on non-pigmented lanugo.
  • Multidisciplinary input โ€” oncology, dermatology, dietetics for accompanying cachexia.

References

  1. Hovenden AL. Hypertrichosis lanuginosa acquisita associated with malignancy. Arch Intern Med. 1987;147:2013-2018.
  2. Pruszkowski A et al. Paraneoplastic hypertrichosis lanuginosa acquisita. Dermatology. 1996;192:50-53.
  3. Wyatt JP, Anderson HF, Greer KE, Cordoro KM. Acquired hypertrichosis lanuginosa as a presenting sign of metastatic prostate cancer. J Am Acad Dermatol. 2007;57:S46-47.
  4. Slee PHT et al. Paraneoplastic hypertrichosis lanuginosa acquisita: uncommon or overlooked? Br J Dermatol. 2007;157:1087-1092.

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