Hair Loss (Alopecia): Or something else? Differential Diagnosis

Blood, blood-forming organs – immune system (D50-D90).

Endocrine, nutritional and metabolic diseases (E00-E90).

  • Biotin deficiency
  • Iron deficiency
  • Hyperthyroidism (hyperthyroidism)
  • Hypoparathyroidism (hypothyroidism of the parathyroid glands).
  • Hypopituitarism (hypofunction of the pituitary gland).
  • Hypothyroidism (underactivity of the thyroid gland)
  • Malnutrition (malnutrition)
  • Protein deficiency
  • Zinc deficiency

Skin and subcutaneous (L00-L99)

  • Alopecia areata (round, localized hair loss).
  • Alopecia androgenetica (androgenetic alopecia).
  • Alopecia specifica in syphilis (lues)
  • Dermatitis seborrhoica (seborrheic dermatitis) – inflammatory skin disease with itching and scaling.
  • Folliculitis decalvans (inflammation of the hair follicles, which occurs rarely and is chronic).
  • Contact dermatitis – skin changes caused by skin contact with certain substances.
  • Lichen follicularis (skin lichen)
  • Pseudopelade Brocq – hair loss with atrophy of the scalp.
  • Telogen effluvium (telogen alopecia) – non-scarring diffuse hair loss due to failure of the cob hairs of hair follicles in the resting phase (hair thinning).
  • Tinea capitis (fungal disease) – head fungus is caused by infection with dermatophytes.
  • Traumatic alopecia – hair loss due to chronic pressure on the hair.

Infectious and parasitic diseases (A00-B99).

  • Microsporiasis (fungal skin disease).
  • Secondary stage of syphilis – infectious disease, the second stage of which is conspicuous by syphilides (skin / mucous membrane manifestations).

Musculoskeletal system and connective tissue (M00-M99).

Neoplasms – tumor diseases (C00-D48)

  • Skin metastases

Psyche – nervous system (F00-F99; G00-G99)

  • Trichotillomania – hair pulling: compulsive pulling out of one’s own hair.

Medications that can lead to alopecia

  • See “Causes” under Medications.